diff --git a/2021/src/day3.rs b/2021/src/day3.rs
index 1800580..3b1a9c7 100644
--- a/2021/src/day3.rs
+++ b/2021/src/day3.rs
@@ -1,7 +1,7 @@
 use color_eyre::eyre;
 
 
-fn most_common_bit(numbers: &Vec<u16>, pos: u8) -> u16 {
+fn most_common_bit(numbers: &Vec<u16>, pos: u16) -> u16 {
     // number of times the bit in question is 1,
     // minus the number of times it's 0
     let mask: u16 = 1 << pos;
@@ -16,18 +16,9 @@ fn most_common_bit(numbers: &Vec<u16>, pos: u8) -> u16 {
 
 
 fn part1(numbers: &Vec<u16>) -> u64 {
-    let mut gamma = 0u16;
-    for i in 0..12 {
-        let mask = most_common_bit(numbers, i) << i;
-        gamma |= mask;
-    }
-
-    // alternate solution: it feels super cool, but it's not any fewer lines than the above, and way less clear :(
-    // let gamma = (0..12)
-    //     .fold(
-    //         0u16,
-    //         |g, i| g | (most_common_bit(numbers, i) << i)
-    //     );
+    let gamma = (0..12).reduce(|g, i|
+         g | most_common_bit(numbers, i) << i
+    ).unwrap(); // unwrap is safe here since this iterator will always have elements
 
     // epsilon is just the bit inverse of gamma, but since these are really 12-bit numbers
     // we have to clear the 4 spurious 1's that come from inverting the original
@@ -36,7 +27,7 @@ fn part1(numbers: &Vec<u16>) -> u64 {
 }
 
 
-fn filter_bit_criteria(numbers: Vec<u16>, bit_pos: u8, bit_value: u16) -> Vec<u16> {
+fn filter_bit_criteria(numbers: Vec<u16>, bit_pos: u16, bit_value: u16) -> Vec<u16> {
     numbers
         .into_iter()
         .filter(|n| (n >> bit_pos) & 1 == bit_value)