diff --git a/src/day1.rs b/src/day1.rs
index ef710f3..c72a3a0 100644
--- a/src/day1.rs
+++ b/src/day1.rs
@@ -11,19 +11,21 @@ pub fn run() {
 
 fn part1(calibration_input: &str) -> usize {
     calibration_input
-        .split("\n")
+        .split('\n')
         .map(|line| {
-            let digits = line.chars().filter(|c| c.is_digit(10)).collect::<String>();
+            let digits = line
+                .chars()
+                .filter(|c| c.is_ascii_digit())
+                .collect::<String>();
 
             if digits.len() == 1 {
                 digits.parse::<usize>().unwrap() * 11
             } else {
-                let tens = digits.chars().nth(0).unwrap().to_digit(10).unwrap();
+                let tens = digits.chars().next().unwrap().to_digit(10).unwrap();
                 let ones = digits.chars().last().unwrap().to_digit(10).unwrap();
                 (tens * 10 + ones) as usize
             }
         })
-        .into_iter()
         .sum()
 }
 
@@ -41,7 +43,7 @@ fn part2(calibration_input: &str) -> usize {
     ];
 
     calibration_input
-        .split("\n")
+        .split('\n')
         .map(|line| {
             let mut index_and_digit: Vec<(usize, usize)> = vec![];
 
@@ -66,7 +68,6 @@ fn part2(calibration_input: &str) -> usize {
                 index_and_digit[0].1 * 10 + index_and_digit.last().unwrap().1
             }
         })
-        .into_iter()
         .sum()
 }