diff --git a/input/03.txt b/input/03.txt
new file mode 100644
index 0000000..13fac46
--- /dev/null
+++ b/input/03.txt
@@ -0,0 +1,323 @@
+..#..#......#..#.......#...#.#.
+...##.....##..#..#....#.##.##.#
+...#...#.##...##.....#.....#.#.
+..#....#.....#...##.##.###.#...
+.#.....#......#..#.##.#...###..
+#..#..#.#......#...........###.
+#......####.#....##........##..
+.#.......#.....#......#...#....
+...#...#.....#.......##.....##.
+#...##.........#.#..##..#..#.##
+#.#.##.........#.#..#.#.....###
+.##..##...#....##.....#..#.....
+........#.......###.#.#.....#.#
+...#.#....#.##..#...##..##..#..
+......#....#........######.#...
+.##...#.#...###......#.#.#..#.#
+........#.##...##.#...#..#...##
+.#..#.#..##....###..#.#.......#
+..#..##..#.#...#.##......#.....
+##.....#..##.#.#..#......##...#
+......................#..#..#..
+..#.##....####.........###.##..
+##..###..#...#....#..#.#...#...
+.##.#......#..#....#........#..
+.#.....#..#..#.#.#....#.....##.
+..........#..#....#..##...#..##
+.#...#.#....#.##..#.....#....#.
+#..............#.#.#..#..#....#
+...#.#...............##........
+#.#.##...#.##..##.....#........
+...#.......###..###..#...#..#..
+####..#.#..##.....##.#.#......#
+.#.#.......#..##.......#.......
+#....#...#.##.#.......#..#.....
+.#...##..#..#..##.......##...#.
+.#..#......#.........#.........
+#.##.#.....#....#..##..#.....#.
+#.#....#.#....#...#.#..#....#..
+#..#.....#.##..#.....#...##...#
+#....#...##.#.........#.#....##
+.......##.##......##.......##..
+#.....#..#........#........#...
+#....#.#..#.#........##.#...#..
+#.......#.#.#.#....#.......##.#
+...#..###..........#...#.#.###.
+....#..#....#...#....##.#.....#
+.#..##.....#..#....##..##...#.#
+#.........#....#.#..###...##...
+.#.#.........#.#.......#.#.#..#
+..........#........##..#.......
+.....#.......#...#.....#..##.##
+...#.........#.............####
+##..#...#..#.#......#...#......
+.#..###...#.#.#.#...#...#......
+....#..##.#....#..#.#..##..##.#
+..#.......#......#..#.......#..
+....###......#...##...#....#...
+..#..#.....#...#..###....#.#..#
+.........##..#.##....#..##..#..
+##...#...#.#.........##......#.
+###..#.#....#......##..##.#...#
+.##...##..#.#.#.#......#..#....
+###......#..#..#.....#..#....#.
+.#.#..##....##........##..#.#..
+###...####.#....#.......###....
+..#....###..#.#.#..#.......##..
+.......#.#...#.....#.#....##.#.
+......#......#.#....#..##..###.
+....####..........#.....#......
+.###.....#...#..#...##.#...###.
+...##....##....###....#.#..#.#.
+##.#..........##.........#.##..
+..#..#.#.###..##..#....##.....#
+..#....##.....#...##....###..##
+....#.......##..#..#..........#
+............#..#.###..#.#......
+...........##......#.#.#...#..#
+...##.##....#...##.##.....#.#..
+.####...#....###...#.....#....#
+.##........#..##..#.#.....#....
+..................#.....#..##..
+..###.....#.##..#..#....##...#.
+...#.##.#.####.#.###.#....#..##
+.#....##..##......####.#####...
+#...#.#....##.........##....#..
+..#.##.....##.............#.##.
+###.....#.#..#..#......#.##.#..
+...#..##.....#...##...#......#.
+.##.#...#......##.#..##....#...
+.....##.....#......#.#.........
+#.....#.....#........##........
+.#......##...#..#.#....###.#..#
+#.####...#....#.........#..#...
+#..##.#.....#.##.##.#....#...#.
+#########..#....#..#...#......#
+..##..##...###.######...##.##..
+##.......#.......#.#....###..#.
+.....#...#.######..#.....#.....
+.#......#..#.............#.##.#
+..###.#.#......##...###........
+.......####.#..##....#........#
+..#......#.##....##.##....#....
+....#......#.#....#..#.#.....##
+####.....#....#.#......#.#.#.##
+#...##....#.#.##.........#....#
+....#..###......#......#...#...
+.....##.#..#..#...#..#.#.#.....
+.##............#.....#.........
+##...#..#.....##.#..#..........
+#.....#####.......#..#....#.#..
+.........#..#.....###........#.
+#....#..#...###........#..#.#..
+...##...#..#...#.##..#.........
+.........#.#.....#.......#...#.
+.#.....#..####....#.##.......##
+...............##....##.##..##.
+............#....#....#...##.#.
+..#...#........#.......#..#....
+##....####....#.##...#..##..#.#
+.#.#.....#......#.#........#.#.
+....#......#.#....##..##.......
+.#..#.#..#..##.....#...........
+..#........#.##..#......##..#..
+...##.#...#...#..#........#....
+##..##....#......#...#..#.#.#.#
+......#.....#..#..#....#.......
+.....##......#..#.#.##...#.....
+...#.....#.#..........#..##...#
+.####.##....#...........#.....#
+.....###..##...#....##..#...#..
+..##...#.#...#..........#..#.#.
+...#..#..............#.##.#....
+##.#....#...#..#....#..........
+.##..........#..#........#.....
+#...#.#......#...#.....##..#...
+.##...#.#.#....###.####..#....#
+.#......#.#...#.#....#.#...#...
+#....##.###.............#.#....
+....#.###..##..##.##...##......
+##....#..###.##.##.....#......#
+..#..#..#......#..#..#.........
+#.##......#.#....#..#..#.......
+....#.#...#..###......##.......
+.###.......##.......#....###...
+..#..#.##..#.#....#..#.#.....#.
+.#..##.##..............#....#..
+#...#.#...#..#.##..##.#.#......
+#...#..#..##..##.###......#....
+.#..#.....#...#....#.....#...#.
+.....#....#..#.....###...#.####
+.#.....#......#...##...#..#....
+.#......#............#.#.......
+....##....#.#..#..#...#..#.#...
+#...#.....###...##...#.##.....#
+.......#.....#....#.......#...#
+#.......###.......#.#..........
+...#.#.###.#........#.###...#..
+....#............#....#..#.....
+#......#.##.#...##.......#..#.#
+.....#....#....#.#.#...###..#..
+.....#.#...#...#.#..#....#.#..#
+.#.......#.#..#...###.......##.
+.......#..#.##.........#.......
+.##.#........#.##...##....#....
+.#....#..#...#......####...#..#
+...#.....#..##.#..#.#....#....#
+...##....#........#.#........#.
+.....#....##..#.##..........#..
+#.....#.#.#......##....##.#..#.
+.#.#.##..#.#....##.#....##.....
+.....#.....#..#.#....#..#....##
+...#........#....#......###.#..
+.....##...#.....##.##.#.#.##...
+...#.....#####....##.#.#.###.#.
+.#..#.#..##...###.........#.#.#
+#...#...#.#..#...#...........#.
+.##..............#...#..#....#.
+....###.........#.#.#....#.....
+..#...##.#.#....##.#..#...#..#.
+..#.....#.#......#....#......#.
+.......##....#.#.##....#...#..#
+##.#.#...#..#......#..#..#....#
+...#.#......#............###.##
+..###..#..##..#...##........#..
+.#...#...##...#....#....##.#..#
+..##...####....#....#..#....#.#
+...#......##....#.........##.#.
+##.#.......#..#..#.............
+..#.#.#.#......#...#.#..##.....
+.#..##.....###...##.#..#......#
+##...#..........#.####....##...
+#..........#...#..##....#......
+....##...#....#..####...#.##.##
+.#.######...##...#..##.........
+....##.........#.......##.##...
+.#.....#.#..........##......#..
+...#..#.#.###..#........#.....#
+..##..#............##.......#..
+......##....##..#.##..#.......#
+.......##....#.......#..#...#.#
+#.#......#.###.....#.##........
+.#..##..........#..#.....#.##..
+..#.#...#....#.........#..##..#
+.#......#.......#...#..#..###..
+......#.##.....#.#......#....#.
+....#....#...#.......#...##.##.
+#....#...##...#..##........###.
+##......#.#..#.......#.......#.
+...##.##..#......#.###..#.#.##.
+.............#..#.............#
+..#.......##..#..#....##...#...
+...............##..##........#.
+##...#.##.......#....#.......##
+....##.##.#.#.....##.....##.##.
+#.#......#.......#..#.#..#.....
+....##....#.##........##.##.#..
+......##....#..##..#..##....##.
+.............#.....#.......#...
+.......###.......#..........#..
+......##.#..#.....#.#...#.#...#
+.#...#..#..###.###...#....##...
+#......#..#.#...#...#.....#..##
+.###.....#..#.#......##..#.##..
+.##.#.....#..#.#..#....##......
+#......#..............#.....#.#
+...#..#....#.....#.....##.#...#
+......#..##..##.....#...#......
+.....####..#..#.##.......#..#.#
+###.#.#........#.......#.....##
+..#.#.#.#...#...#........#....#
+....##.#.#..#...##.....#......#
+#..#.##....#..#.##..####.......
+...####.#...#......#......##..#
+#....#.#..###......#..#..##..#.
+...........#....#...#......#...
+......###.#.....#.#....#.#...#.
+.......#.##..............#..##.
+..##...........#..#.#...#.....#
+#..#............##.........#.#.
+.......###.#...#.#...#.#.#...#.
+..#...##.......#..#......#.#.##
+#.#...#.....#...##.#.#.......##
+.#.#.##...#..##.#......#.......
+#.......#.......#.#....#.....#.
+.....#..#..#.......#..#........
+##...##...##......#..##.###....
+..#...#.###.#.###..#.....###...
+.....####.......#.#.....##....#
+....#....#.#....#...#..#.#..#..
+..##.....#....#.#.#.###...#....
+......#.#....#.#..#....#.#..#..
+#...#...#....#.......#......#.#
+#..#.#......#..#...........#.##
+...............#....#.....#...#
+.#.#.#...#.##...#.#.#..#....#..
+...#.#.####..##.#...##.........
+##.........##.##.....##....#...
+................#...#.##.#.#..#
+.#..#....#...#..#..#..###.#..#.
+...#..#.##.#.####..........#..#
+........#....##......#..#.#....
+........##.........#..#..#..#.#
+#......#.#...#...#...##.....#..
+#...#.....#..#..##.#...#.#.#...
+....#..##...##.....#...#.#.....
+..#..##....#....#...#....#.....
+.#..#...##.......###...#...#...
+.#......#......#..##..#..##....
+....##....#..#.#....#.#..##....
+###......#...........#.....###.
+.....#...#..##.#..#..#.....#..#
+#.#....#...........#.##..#..###
+#....#...###.#...#..##..#.....#
+.#....#......##.#..#....#.#....
+....#.#....#..#.#....#..#..#...
+..#......#..#.#.#....#.........
+.#...#.#.....#........#.#...###
+....#..##.......#.###....##....
+#.#.......#......#.###........#
+#.........#.....####.##..#..#..
+.#.#..##...#.#.....##.#.#..#...
+.#..#..#..#.##..#...###.#...#..
+.....##..##..##..#.#.#.....###.
+.#..#...#..#......##.#.........
+....#..##....#.##.........#...#
+........#...#...###.........##.
+#.........#..##....#.#...#.....
+.......#.......#..#.......#....
+#......##......#.#.##..........
+.#..##..####...#.....####.....#
+........#.#....#..##..###.#...#
+.#...#...#.........###..#...#.#
+#.........#....##...#..........
+.#.#....#..........#...........
+.#.#..........#.##.....#.##....
+..#....#...##..###..........##.
+.#.#..#.##..#..#.##.##..##.....
+........#...#....#...#.#..##...
+......#......##..#..#.....#..#.
+.##.#....#...#....#...#..##..##
+##............#..........###...
+....#.......#.#..#.#####.....#.
+#......#.....#...#........#....
+..##.....###..#.#.#.#....#....#
+#...#...#.#..#..#....#..#......
+......#....#...#..#....#####...
+....#.......##....#....##......
+.....##...#.##.#.....##....#...
+.#....###.#..##...##.##.......#
+....#.#.#.##.............#..##.
+...........##......#...#.#.##..
+....##......#....#....##..##.#.
+.#.#...#.....##.....#.........#
+#.#..........#.......#.##...#..
+....#.##..#.#....#.....#...#...
+##.............##.......#.##.#.
+....#...#.....##...#..........#
+##..#...#...#.#.##...#.......##
+..#........#.....###...##..##.#
+.....#...##.#.#.##.....#...#...
+####.###...##..##...#..#..#..##
+......#..#..#.........#...#.#..
+....###.....##.##....#.##.....#
diff --git a/src/03.rkt b/src/03.rkt
new file mode 100644
index 0000000..84c4001
--- /dev/null
+++ b/src/03.rkt
@@ -0,0 +1,54 @@
+#lang racket
+
+(require "../lib.rkt")
+
+(define test
+  (lists->vectors
+   (map string->list
+        '("..##......."
+          "#...#...#.."
+          ".#....#..#."
+          "..#.#...#.#"
+          ".#...##..#."
+          "..#.##....."
+          ".#.#.#....#"
+          ".#........#"
+          "#.##...#..."
+          "#...##....#"
+          ".#..#...#.#"))))
+
+(define input (lists->vectors (map string->list (problem-input 3))))
+
+(define (trees grid right down)
+  (define width (vector-length (vector-ref grid 0)))
+  (for/sum ([i (range 0 (vector-length grid) down)])
+    (if (char=? #\#
+                (vector-ref (vector-ref grid i)
+                            (% (* (/ i down) right) width)))
+        1 0)))
+
+(define (test-input grid)
+  (define (print-test right down)
+    (let ([trees (trees grid right down)])
+      (printf "Part 2 test (~a right, ~a down): ~a\n"
+              right down trees)
+      trees))
+  (printf "Part 2 test: ~a\n"
+          (* (print-test 1 1)
+             (print-test 3 1)
+             (print-test 5 1)
+             (print-test 7 1)
+             (print-test 1 2))))
+
+(define part1
+  (trees input 3 1))
+
+(define part2
+  (* (trees input 1 1)
+     (trees input 3 1)
+     (trees input 5 1)
+     (trees input 7 1)
+     (trees input 1 2)))
+
+(test-input test)
+(show-solution part1 part2)
diff --git a/template.rkt b/template.rkt
new file mode 100644
index 0000000..b690640
--- /dev/null
+++ b/template.rkt
@@ -0,0 +1,14 @@
+#lang racket
+
+(require "../lib.rkt")
+
+(define (parse in) in)
+
+(define input (parse (problem-input 0)))
+
+(define part1 #f)
+
+(define part2 #f)
+
+(show-solution part1 part2)
+