diff --git a/13.rb b/13.rb
new file mode 100644
index 0000000..251ba2b
--- /dev/null
+++ b/13.rb
@@ -0,0 +1,42 @@
+input = File.read('input_13.txt').gsub(" ","").split("\n").map do |x| x.split(":") end.to_h
+#input = {0 => 3, 1 => 2, 4 => 4, 6 => 4}
+input = input.map do |k, v| [k.to_i, v.to_i] end.to_h
+
+def round_trip a
+    (a*2)-2
+end
+
+def do_count input
+  input.keys.reduce(0) do |mem, time|
+   p "Time: " + time.to_s
+   p "Range: " + input[time].to_s
+   p "Calc: " + (time % (round_trip input[time])).to_s
+    if time % (round_trip input[time]) == 0 then
+      cost = time * (input[time])
+      mem += cost
+    else mem
+    end
+  end
+end
+
+def do_count_with_delay input
+  i = 0
+  while true do
+    res = 0
+    input.keys.each do |time|
+      if (time+i) % (round_trip input[time]) == 0 then
+        res = 1
+      end
+    end
+    if res == 0 then
+      return i
+    end
+    i += 1
+  end
+end
+
+
+
+p do_count input
+p do_count_with_delay input
+