diff --git a/2021/src/day01.rs b/2021/src/day01.rs
index 1c3acd1..0f32150 100644
--- a/2021/src/day01.rs
+++ b/2021/src/day01.rs
@@ -2,28 +2,22 @@ use std::io::Read;
 
 use crate::common::LineParser;
 
-fn read_input(input: &mut dyn Read) -> Vec<u32> {
-    LineParser::new(input).collect()
+fn part_generic(input: &mut dyn Read, window: usize) -> String {
+    let numbers: Vec<u32> = LineParser::new(input).collect();
+
+    numbers
+        .windows(window)
+        .filter(|w| w.last() > w.first())
+        .count()
+        .to_string()
 }
 
 pub fn part1(input: &mut dyn Read) -> String {
-    let numbers = read_input(input);
-
-    numbers
-        .windows(2)
-        .filter(|w| w[1] > w[0])
-        .count()
-        .to_string()
+    part_generic(input, 2)
 }
 
 pub fn part2(input: &mut dyn Read) -> String {
-    let numbers = read_input(input);
-
-    numbers
-        .windows(4)
-        .filter(|w| w[3] > w[0])
-        .count()
-        .to_string()
+    part_generic(input, 4)
 }
 
 #[cfg(test)]