diff --git a/src/days/day03.zig b/src/days/day03.zig
index 34f4449..de49283 100644
--- a/src/days/day03.zig
+++ b/src/days/day03.zig
@@ -6,35 +6,33 @@ pub fn run(_: std.mem.Allocator) !void {
     const input = @embedFile("./input/day03.txt");
     var lines = std.mem.tokenizeScalar(u8, input, '\n');
 
-    var accumulator: u32 = 0;
+    var accumulator: u64 = 0;
+
+    const nr_of_digits = 12;
 
     while (lines.next()) |line| {
-        var first_digit: u8 = 0;
-        var first_digit_index: usize = 0;
-        for (line[0..line.len - 1], 0..) |c, i| {
-            const digit = try std.fmt.charToDigit(c, 10);
-            if (digit > first_digit) {
-                first_digit = digit;
-                first_digit_index = i;
-            }
-        }
-        std.debug.print("first = {d}\n", .{first_digit});
+        var joltage: u64 = 0;
 
-        var second_digit: u8 = 0;
-        if (first_digit_index == line.len - 2) {
-            const c = line[line.len - 1];
-            second_digit = try std.fmt.charToDigit(c, 10);
-        } else {
-            for (line[first_digit_index + 1..]) |c| {
-                const digit = try std.fmt.charToDigit(c, 10);
-                if (digit > second_digit) {
-                    second_digit = digit;
+        var start: usize = 0;
+        for (0..nr_of_digits) |i| {
+            const end = line.len - (nr_of_digits - i) + 1;
+
+            std.debug.print("checking {d} to {d}\n", .{start, end});
+
+            var digit: u8 = 0;
+            for (line[start..end], start..) |c, di| {
+                const d = try std.fmt.charToDigit(c, 10);
+                if (d > digit) {
+                    digit = d;
+                    start = di + 1;
                 }
             }
-        }
-        std.debug.print("second = {d}\n", .{second_digit});
+            std.debug.print("digit = {d}\n", .{digit});
 
-        const joltage = first_digit * 10 + second_digit;
+            joltage += digit * std.math.pow(u64, 10, nr_of_digits - (i + 1));
+        }
+
+        std.debug.print("joltage = {d}\n", .{joltage});
         accumulator += joltage;
     }