diff --git a/Cargo.lock b/Cargo.lock
index bbedd73..a45f174 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5,3 +5,50 @@ version = 3
 [[package]]
 name = "advent-of-code-2024"
 version = "0.1.0"
+dependencies = [
+ "regex",
+]
+
+[[package]]
+name = "aho-corasick"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "memchr"
+version = "2.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
+
+[[package]]
+name = "regex"
+version = "1.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b544ef1b4eac5dc2db33ea63606ae9ffcfac26c1416a2806ae0bf5f56b201191"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.4.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "809e8dc61f6de73b46c85f4c96486310fe304c434cfa43669d7b40f711150908"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b15c43186be67a4fd63bee50d0303afffcef381492ebe2c5d87f324e1b8815c"
diff --git a/Cargo.toml b/Cargo.toml
index 6cdd29c..3f298fa 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,3 +4,4 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+regex = "1.11.1"
diff --git a/apollo.py b/apollo.py
new file mode 100644
index 0000000..b05bbc7
--- /dev/null
+++ b/apollo.py
@@ -0,0 +1,23 @@
+import re
+with open("input-xlarge", "r") as inputFile:
+    memory = inputFile.read()
+    do_memory = memory.split("don't()")
+
+
+# part 1
+def apply_multipliers(s: str):
+    prods = []
+    multipliers = re.findall("mul\(\d{1,3},\d{1,3}\)", s)
+    for m in multipliers:
+        nums = list(map(int, re.findall("\d+", m)))
+        prods.append(nums[0] * nums[1])
+    return sum(prods)
+
+
+# part 2
+sum_dos = apply_multipliers(do_memory[0])
+for line in do_memory[1:]:
+    if "do()" in line:
+        split_line = "".join(line.split('do()')[1:])
+        sum_dos += apply_multipliers(split_line)
+print(sum_dos)
diff --git a/d/README.md b/d/README.md
deleted file mode 100644
index ee303f5..0000000
--- a/d/README.md
+++ /dev/null
@@ -1,9 +0,0 @@
-# Advent of code 2024
-
-Usage:
-
-    rustc dp1.rs
-    cat input.txt | dp1.rs
-
-## Day 
-
diff --git a/d/d1p1.rs b/d/d1p1.rs
deleted file mode 100644
index fdb696a..0000000
--- a/d/d1p1.rs
+++ /dev/null
@@ -1,22 +0,0 @@
-use std::collections::BinaryHeap;
-use std::io;
-
-fn main() -> io::Result<()> {
-    let mut l1 = BinaryHeap::<u64>::new();
-    let mut l2 = BinaryHeap::<u64>::new();
-    for line in io::stdin().lines() {
-        let line = line?;
-        let parts: Vec<&str> = line.trim().split_whitespace().collect();
-        let (n1, n2) = (parts[0], parts[1]);
-        l1.push(n1.parse().unwrap());
-        l2.push(n2.parse().unwrap());
-    }
-    let l1 = l1.into_sorted_vec();
-    let l2 = l2.into_sorted_vec();
-    let mut sum = 0;
-    for (n1, n2) in l1.into_iter().zip(l2.into_iter()) {
-        sum += n1.abs_diff(n2);
-    }
-    println!("{}", sum);
-    Ok(())
-}
diff --git a/d/d1p1.txt b/d/d1p1.txt
deleted file mode 100644
index dfca0b1..0000000
--- a/d/d1p1.txt
+++ /dev/null
@@ -1,6 +0,0 @@
-3   4
-4   3
-2   5
-1   3
-3   9
-3   3
\ No newline at end of file
diff --git a/d/d1p2.rs b/d/d1p2.rs
deleted file mode 100644
index 0c7f9e2..0000000
--- a/d/d1p2.rs
+++ /dev/null
@@ -1,21 +0,0 @@
-use std::collections::HashMap;
-use std::io;
-
-fn main() -> io::Result<()> {
-    let mut l1: Vec<u64> = vec!();
-    let mut l2: HashMap<u64, u64> = HashMap::default();
-    for line in io::stdin().lines() {
-        let line = line?;
-        let parts: Vec<&str> = line.trim().split_whitespace().collect();
-        let (n1, n2) = (parts[0], parts[1]);
-        l1.push(n1.parse().unwrap());
-        let v = l2.entry(n2.parse::<u64>().unwrap()).or_insert(0);
-        *v += 1;
-    }
-    let mut sum = 0;
-    for n1 in l1.into_iter() {
-        sum += n1*l2.get(&n1).unwrap_or(&0);
-    }
-    println!("{}", sum);
-    Ok(())
-}
diff --git a/d/d2p1.rs b/d/d2p1.rs
deleted file mode 100644
index 627f603..0000000
--- a/d/d2p1.rs
+++ /dev/null
@@ -1,58 +0,0 @@
-use advent_of_code_2024::{make_main, SResult};
-
-make_main!();
-
-// CODE
-
-#[derive(PartialEq)]
-enum Direction {
-    Up,
-    Down,
-}
-
-impl Direction {
-    fn from(a: usize, b: usize) -> Self {
-        if a > b {
-            Direction::Down
-        } else {
-            Direction::Up
-        }
-    }
-}
-
-fn solve(lines: Vec<String>) -> SResult<usize> {
-    let mut failed = 0;
-    for line in lines.iter() {
-        let reports: Vec<usize> = line.split_whitespace().map(|v| v.parse::<usize>().unwrap()).collect();
-        let mut i = 0;
-        let direction = Direction::from(reports[0], reports[1]);
-        while i + 1 < reports.len() {
-            let delta = reports[i].abs_diff(reports[i+1]);
-            if delta < 1 || delta > 3 {
-                failed += 1;
-                break;
-            }
-            if direction != Direction::from(reports[i], reports[i+1]) {
-                failed += 1;
-                break;
-            }
-            i += 1;
-        }
-    }
-    Ok(lines.len() - failed)
-}
-
-// CODE
-
-#[cfg(test)]
-mod tests {
-    use advent_of_code_2024::input;
-
-    use super::*;
-    #[test]
-    fn sample_input() {
-        let strings: Vec<String> = input!("d2p1.txt");
-        let got = solve(strings).unwrap();
-        assert_eq!(got, 2);
-    }
-}
\ No newline at end of file
diff --git a/d/d2p1.txt b/d/d2p1.txt
deleted file mode 100644
index 82cd679..0000000
--- a/d/d2p1.txt
+++ /dev/null
@@ -1,6 +0,0 @@
-7 6 4 2 1
-1 2 7 8 9
-9 7 6 2 1
-1 3 2 4 5
-8 6 4 4 1
-1 3 6 7 9
\ No newline at end of file
diff --git a/d/d2p2.rs b/d/d2p2.rs
deleted file mode 100644
index 9962ddf..0000000
--- a/d/d2p2.rs
+++ /dev/null
@@ -1,78 +0,0 @@
-use advent_of_code_2024::{make_main, SResult};
-
-make_main!();
-
-#[derive(PartialEq, Clone, Copy)]
-enum Direction {
-    Up,
-    Down,
-}
-
-impl Direction {
-    fn from(a: usize, b: usize) -> Self {
-        if a > b {
-            Direction::Down
-        } else {
-            Direction::Up
-        }
-    }
-}
-
-fn solve(lines: Vec<String>) -> SResult<usize> {
-    let mut fail_count = 0;
-    for line in lines.iter() {
-        let reports: Vec<usize> = line
-            .split_whitespace()
-            .map(|v| v.parse::<usize>().unwrap())
-            .collect();
-        let problems = match test(&reports) {
-            // Cool, nothing to see here
-            Ok(_) => continue,
-            Err(e) => e,
-        };
-        let mut pass = false;
-        for problem in problems {
-            let mut l1 = reports.clone();
-            l1.remove(problem);
-            if test(&l1).is_ok() {
-                pass = true;
-                break;
-            }
-        }
-        if !pass {
-            fail_count += 1;
-        }
-    }
-    Ok(lines.len() - fail_count)
-}
-
-// Tests the report, and returns indexes around where a failure is detected.
-fn test(reports: &[usize]) -> Result<(), Vec<usize>> {
-    let mut i = 0;
-    let direction = Direction::from(reports[0], reports[1]);
-    while i + 1 < reports.len() {
-        let delta = reports[i].abs_diff(reports[i + 1]);
-        if delta < 1 || delta > 3 || direction != Direction::from(reports[i], reports[i + 1]) {
-            let mut errs = vec![i, i + 1];
-            if i > 0 {
-                errs.push(i - 1);
-            }
-            return Err(errs);
-        }
-        i += 1;
-    }
-    Ok(())
-}
-
-#[cfg(test)]
-mod tests {
-    use advent_of_code_2024::input;
-
-    use super::*;
-    #[test]
-    fn sample_input() {
-        let strings: Vec<String> = input!("d2p1.txt");
-        let got = solve(strings).unwrap();
-        assert_eq!(got, 4);
-    }
-}
diff --git a/src/bin/d3p1.rs b/src/bin/d3p1.rs
new file mode 100644
index 0000000..a3e8bd5
--- /dev/null
+++ b/src/bin/d3p1.rs
@@ -0,0 +1,29 @@
+use advent_of_code_2024::{make_main, SResult};
+use regex::Regex;
+
+make_main!();
+
+fn solve(lines: Vec<String>) -> SResult<usize> {
+    let mut result = 0;
+    let re = Regex::new(r"mul\((?<mul1>\d{1,3}),(?<mul2>\d{1,3})\)")?;
+    for line in lines {
+        for caps in re.captures_iter(&line) {
+            result += caps["mul1"].parse::<usize>().unwrap() * caps["mul2"].parse::<usize>().unwrap();
+        }
+    }
+    Ok(result)
+}
+
+
+#[cfg(test)]
+mod tests {
+    use advent_of_code_2024::input;
+
+    use super::*;
+    #[test]
+    fn sample_input() {
+        let strings: Vec<String> = input!("d3p1.txt");
+        let got = solve(strings).unwrap();
+        assert_eq!(got, 161);
+    }
+}
diff --git a/src/bin/d3p1.txt b/src/bin/d3p1.txt
new file mode 100644
index 0000000..2e1a90a
--- /dev/null
+++ b/src/bin/d3p1.txt
@@ -0,0 +1 @@
+xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))
\ No newline at end of file
diff --git a/src/bin/d3p1hard.rs b/src/bin/d3p1hard.rs
new file mode 100644
index 0000000..7019f14
--- /dev/null
+++ b/src/bin/d3p1hard.rs
@@ -0,0 +1,94 @@
+use advent_of_code_2024::{make_main, SResult};
+
+make_main!();
+
+type PResult<'a, T> = Result<(&'a str, T), ()>;
+
+fn literal<'a, 'b>(p: &'a str, lit: &'b str) -> PResult<'a, ()> {
+    if p.len() < lit.len() {
+        Err(())
+    } else {
+        let (found, rest) = p.split_at(lit.len());
+        if found == lit {
+            Ok((rest, ()))
+        } else {
+            Err(())
+        }
+    }
+}
+
+fn next(p: &str) -> PResult<char> {
+    let mut chars = p.chars();
+    let next = chars.next().ok_or(())?;
+    Ok((chars.as_str(), next))
+}
+
+fn int(mut p: &str) -> PResult<usize> {
+    let (_p, total) = next(p)?;
+    let mut total = total.to_digit(10).ok_or(())?;
+    p = _p;
+    let mut i = 1;
+    while let Ok((_p, digit)) = next(p) {
+        if !digit.is_digit(10) {
+            break;
+        }
+        total = (total * 10) + digit.to_digit(10).ok_or(())?;
+        p = _p;
+
+        // We only accept integers between 1 and 3 digits
+        i += 1;
+        if i > 3 {
+            return Err(());
+        }
+    }
+    Ok((p, total as usize))
+}
+
+fn mul(p: &str) -> PResult<usize> {
+    let (p, _) = literal(p, "mul(")?;
+    let (p, mul1) = int(p)?;
+    let (p, _) = literal(p, ",")?;
+    let (p, mul2) = int(p)?;
+    let (p, _) = literal(p, ")")?;
+    Ok((p, mul1*mul2))
+}
+
+fn solve(lines: Vec<String>) -> SResult<usize> {
+    let mut result = 0;
+    let mut enabled = true;
+    for line in lines {
+        let mut line = line.as_str();
+        while line.len() > 0 {
+            if let Ok(val) = mul(&line) {
+                if enabled {
+                    result += val.1;
+                }
+                line = val.0;
+            } else if let Ok(val) = literal(&line, "do()") {
+                enabled = true;
+                line = val.0;
+            } else if let Ok(val) = literal(&line, "don't()") {
+                enabled = false;
+                line = val.0;
+            } else {
+                let n = next(line).unwrap();
+                line = n.0;
+            }
+        }
+    }
+    Ok(result)
+}
+
+
+#[cfg(test)]
+mod tests {
+    use advent_of_code_2024::input;
+
+    use super::*;
+    #[test]
+    fn sample_input() {
+        let strings: Vec<String> = input!("d3p2.txt");
+        let got = solve(strings).unwrap();
+        assert_eq!(got, 48);
+    }
+}
diff --git a/src/bin/d3p2.rs b/src/bin/d3p2.rs
new file mode 100644
index 0000000..536c48e
--- /dev/null
+++ b/src/bin/d3p2.rs
@@ -0,0 +1,36 @@
+use advent_of_code_2024::{make_main, SResult};
+use regex::Regex;
+
+make_main!();
+
+fn solve(lines: Vec<String>) -> SResult<usize> {
+    let mut result = 0;
+    let re = Regex::new(r"(?<do>do\(\))|(?<dont>don't\(\))|mul\(((?<mul1>\d{1,3})),((?<mul2>\d{1,3}))\)")?;
+    let mut enabled = true;
+    for line in lines {
+        for caps in re.captures_iter(&line) {
+            if caps.name("do").is_some() {
+                enabled = true;
+            } else if caps.name("dont").is_some() {
+                enabled = false;
+            } else if caps.name("mul1").is_some() && enabled {
+                result += caps["mul1"].parse::<usize>().unwrap() * caps["mul2"].parse::<usize>().unwrap();
+            }
+        }
+    }
+    Ok(result)
+}
+
+
+#[cfg(test)]
+mod tests {
+    use advent_of_code_2024::input;
+
+    use super::*;
+    #[test]
+    fn sample_input() {
+        let strings: Vec<String> = input!("d3p2.txt");
+        let got = solve(strings).unwrap();
+        assert_eq!(got, 48);
+    }
+}
diff --git a/src/bin/d3p2.txt b/src/bin/d3p2.txt
new file mode 100644
index 0000000..b774ec9
--- /dev/null
+++ b/src/bin/d3p2.txt
@@ -0,0 +1 @@
+xmul(2,4)&mul[3,7]!^don't()_mul(5,5)+mul(32,64](mul(11,8)undo()?mul(8,5))
\ No newline at end of file
diff --git a/src/bin/d4p1.rs b/src/bin/d4p1.rs
new file mode 100644
index 0000000..2140d72
--- /dev/null
+++ b/src/bin/d4p1.rs
@@ -0,0 +1,61 @@
+use advent_of_code_2024::{make_main, SResult};
+
+make_main!();
+
+fn solve(lines: Vec<String>) -> SResult<usize> {
+    // Convert to a grid of chars for easy searching
+    let mut grid = vec!();
+    for line in lines {
+        let line: Vec<char> = line.chars().collect();
+        grid.push(line);
+    }
+    let mut total = 0;
+    let word: Vec<char> = "XMAS".chars().collect();
+    for x in 0..grid.len() {
+        for y in 0..grid[x].len() {
+            for vel in [(1, 0), (-1, 0), (0, 1), (0, -1), (1, 1), (-1, -1), (-1, 1), (1, -1)] {
+                let mut matches = 0;
+                let mut pos = (x, y);
+                for c in &word {
+                    if grid[pos.0][pos.1] != *c {
+                        break;
+                    }
+                    matches += 1;
+                    if let Some(_pos) = next(pos, vel, grid.len()) {
+                        pos = _pos;
+                    } else {
+                        break;
+                    }
+                }
+                if matches == word.len() {
+                    total += 1;
+                }
+            }
+        }
+    }
+    Ok(total)
+}
+
+fn next((x, y): (usize, usize), (xvel, yvel): (i64, i64), width: usize) -> Option<(usize, usize)> {
+    let x = x as i64 + xvel;
+    let y = y as i64 + yvel;
+    if x < 0 || y < 0 || x == width as i64 || y == width as i64 {
+        None
+    } else {
+        Some((x as usize, y as usize))
+    }
+}
+
+
+#[cfg(test)]
+mod tests {
+    use advent_of_code_2024::input;
+
+    use super::*;
+    #[test]
+    fn sample_input() {
+        let strings: Vec<String> = input!("d4p1.txt");
+        let got = solve(strings).unwrap();
+        assert_eq!(got, 18);
+    }
+}
diff --git a/src/bin/d4p1.txt b/src/bin/d4p1.txt
new file mode 100644
index 0000000..c41c5ea
--- /dev/null
+++ b/src/bin/d4p1.txt
@@ -0,0 +1,10 @@
+MMMSXXMASM
+MSAMXMSMSA
+AMXSXMAAMM
+MSAMASMSMX
+XMASAMXAMM
+XXAMMXXAMA
+SMSMSASXSS
+SAXAMASAAA
+MAMMMXMMMM
+MXMXAXMASX
\ No newline at end of file
diff --git a/src/bin/d4p2.rs b/src/bin/d4p2.rs
new file mode 100644
index 0000000..6c046ae
--- /dev/null
+++ b/src/bin/d4p2.rs
@@ -0,0 +1,73 @@
+use advent_of_code_2024::{make_main, SResult};
+
+make_main!();
+
+fn solve(lines: Vec<String>) -> SResult<usize> {
+    // Convert to a grid of chars for easy searching
+    let mut grid = vec!();
+    for line in lines {
+        let line: Vec<char> = line.chars().collect();
+        grid.push(line);
+    }
+    let mut total = 0;
+    let word: Vec<char> = "XMAS".chars().collect();
+    for x in 0..grid.len() {
+        for y in 0..grid[x].len() {
+            if grid[x][y] != 'A' {
+                continue;
+            }
+            let mut count = 0;
+            for vel in [(1, 1), (1, -1), (-1, -1), (-1, 1)] {
+                if let Some(pos) = next((x, y), vel, grid.len()) {
+                    if check_mas(&grid, pos, (-1*vel.0, -1*vel.1)) {
+                        count += 1;
+                    }
+                }
+            }
+            if count == 2 {
+                total += 1;
+            }
+        }
+    }
+    Ok(total)
+}
+
+fn check_mas(grid: &[Vec<char>], mut pos: (usize, usize), vel: (i64, i64)) -> bool {
+    let mut matches = 0;
+    for c in "MAS".chars() {
+        if c != grid[pos.0][pos.1] {
+            break;
+        }
+        matches += 1;
+        if let Some(_pos) = next(pos, vel, grid.len()) {
+            pos = _pos;
+        } else {
+            break;
+        }
+    }
+    matches == "MAS".len()
+}
+
+fn next((x, y): (usize, usize), (xvel, yvel): (i64, i64), width: usize) -> Option<(usize, usize)> {
+    let x = x as i64 + xvel;
+    let y = y as i64 + yvel;
+    if x < 0 || y < 0 || x == width as i64 || y == width as i64 {
+        None
+    } else {
+        Some((x as usize, y as usize))
+    }
+}
+
+
+#[cfg(test)]
+mod tests {
+    use advent_of_code_2024::input;
+
+    use super::*;
+    #[test]
+    fn sample_input() {
+        let strings: Vec<String> = input!("d4p1.txt");
+        let got = solve(strings).unwrap();
+        assert_eq!(got, 9);
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 5d615af..5a0c2ac 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -18,4 +18,16 @@ macro_rules! input {
     };
 }
 
-pub type SResult<T> = Result<T, Box<dyn std::error::Error>>;
\ No newline at end of file
+pub type SResult<T> = Result<T, Box<dyn std::error::Error>>;
+
+pub type Pair<T = usize> = (T, T);
+
+pub fn next((x, y): Pair, (xvel, yvel): Pair<i64>, width: usize) -> Option<Pair> {
+    let x = x as i64 + xvel;
+    let y = y as i64 + yvel;
+    if x < 0 || y < 0 || x == width as i64 || y == width as i64 {
+        None
+    } else {
+        Some((x as usize, y as usize))
+    }
+}
\ No newline at end of file