diff --git a/day04/Day04.rs b/day04/Day04.rs
index 66674ed..7303359 100644
--- a/day04/Day04.rs
+++ b/day04/Day04.rs
@@ -3,14 +3,8 @@ fn main() {
     part2(246515, 739105);
 }
 
-fn digit_count(n: usize) -> u32 {
-    if n == 0 { 1 } else { (n as f64).log10().floor() as u32 + 1 }
-}
-
 fn digit_n(digit: u32, n: usize) -> usize {
-    let digit_count = digit_count(n);
-    println!("{} {} {}", n, digit_count, digit);
-    let place = 10usize.pow(digit_count - digit);
+    let place = 10usize.pow(5 - digit);
     (n / place) % 10
 }
 
@@ -26,8 +20,7 @@ fn is_increasing(n: usize) -> bool {
 }
 
 fn has_double(n: usize) -> bool {
-    let digit_count = digit_count(n);
-    for digit in 0 .. digit_count {
+    for digit in 0 .. 5 {
         let this = digit_n(digit, n);
         let next = digit_n(digit + 1, n);
         if next == this {
@@ -38,7 +31,15 @@ fn has_double(n: usize) -> bool {
 }
 
 fn has_strict_double(n: usize) -> bool {
-    false
+    let mut doubles: [usize; 10] = Default::default();
+    for digit in 0 .. 5 {
+        let this = digit_n(digit, n);
+        let next = digit_n(digit + 1, n);
+        if next == this {
+            doubles[this] += 1;
+        }
+    }
+    doubles.contains(&1)
 }
 
 fn part1(lower: usize, upper: usize) {
@@ -53,11 +54,6 @@ fn part1(lower: usize, upper: usize) {
 
 fn part2(lower: usize, upper: usize) {
     let mut count = 0;
-
-    for n in &[112233, 123444, 111122, 144455, 114444] {
-        println!("{} has_strict_double: {}", n, has_strict_double(*n));
-    }
-
     for n in lower ..= upper {
         if is_increasing(n) && has_strict_double(n) {
             count += 1;