diff --git a/.gitignore b/.gitignore
index d81f12e..8e094ab 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 /target
 /.idea
+/input
diff --git a/Cargo.lock b/Cargo.lock
index 38d1eb5..68b0027 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5,3 +5,21 @@ version = 4
 [[package]]
 name = "advent-of-rust-2024"
 version = "0.1.0"
+dependencies = [
+ "itertools",
+]
+
+[[package]]
+name = "either"
+version = "1.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "60b1af1c220855b6ceac025d3f6ecdd2b7c4894bfe9cd9bda4fbb4bc7c0d4cf0"
+
+[[package]]
+name = "itertools"
+version = "0.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "413ee7dfc52ee1a4949ceeb7dbc8a33f2d6c088194d9f922fb8318faf1f01186"
+dependencies = [
+ "either",
+]
diff --git a/Cargo.toml b/Cargo.toml
index 8f7f551..ea8ff06 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,3 +4,4 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+itertools = "0.13.0"
diff --git a/src/main.rs b/src/main.rs
index e7a11a9..02609a0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,46 @@
+use itertools::Itertools;
+use std::fs::read_to_string;
+
 fn main() {
-    println!("Hello, world!");
+    let input = read_to_string("input/day01.txt").unwrap();
+    let part1 = part1(&input);
+    println!("part1: {}", part1);
+}
+
+type Int = i32;
+
+fn part1(input: &str) -> Int {
+    let (mut l, mut r) = input
+        .trim()
+        .lines()
+        .map(|line| line.split_ascii_whitespace().collect_tuple().unwrap())
+        .map(|(x, y)| (x.parse::<Int>().unwrap(), y.parse::<Int>().unwrap()))
+        .fold((vec![], vec![]), |(mut v1, mut v2), (a, b)| {
+            v1.push(a);
+            v2.push(b);
+            (v1, v2)
+        });
+
+    l.sort();
+    r.sort();
+
+    l.into_iter()
+        .zip(r.into_iter())
+        .map(|(l, r)| (l - r).abs())
+        .sum()
+}
+
+#[cfg(test)]
+const TEST_INPUT: &str = r"
+3   4
+4   3
+2   5
+1   3
+3   9
+3   3
+";
+
+#[test]
+fn test() {
+    assert_eq!(part1(TEST_INPUT), 11);
 }