diff --git a/day3/part1/main.d b/day3/part1/main.d
index a6766f1..df48eda 100644
--- a/day3/part1/main.d
+++ b/day3/part1/main.d
@@ -5,14 +5,13 @@ void main()
     File("input", "r").byLineCopy.array.countTrees(3, 1).writeln;
 }
 
-ulong countTrees(T)(T input, int angleX, int angleY)
+ulong countTrees(const char[][] input, int angleX, int angleY)
 in(input.length > 0)
 {
     immutable width = input[0].length;
-    size_t count = 0;
     size_t x = 0;
     return input.stride(angleY).map!((row) {
-        auto result = row[x];
+        immutable result = row[x];
         x = (x + angleX) % width;
         return result;
     })
@@ -35,5 +34,4 @@ unittest
 .#..#...#.#`.byChar.splitter("\n").map!array.array;
 
     assert(input.countTrees(3, 1) == 7);
-
 }
diff --git a/day3/part2/main.d b/day3/part2/main.d
index 76a1315..088c826 100644
--- a/day3/part2/main.d
+++ b/day3/part2/main.d
@@ -19,7 +19,7 @@ in(input.length > 0)
     immutable width = input[0].length;
     size_t x = 0;
     return input.stride(angleY).map!((row) {
-        auto result = row[x];
+        immutable result = row[x];
         x = (x + angleX) % width;
         return result;
     })