diff --git a/d13.py b/d13.py
new file mode 100755
index 0000000..f158bab
--- /dev/null
+++ b/d13.py
@@ -0,0 +1,20 @@
+#!/usr/bin/env python3
+
+from sys import argv
+
+i = open(argv[1]).read().split("\n")
+a = int(i[0].strip())
+b = [int(x) if x != "x" else None for x in i[1].strip().split(",")]
+
+e = sorted([(x, x-(a%x)) for x in b if x], key=lambda x: x[1])[0]
+print(e[0]*e[1])
+
+ma = [(i, x) for i, x in enumerate(b) if x]
+ma.sort(key=lambda x: x[1], reverse=True)
+s = ma[0][1]-ma[0][0]
+m = ma[0][1]
+for i, x in ma[1:]:
+    while x-(s%x) != (i%x if i%x != 0 else x):
+        s += m
+    m *= x
+print(s)
diff --git a/d13_input.txt b/d13_input.txt
new file mode 100644
index 0000000..85d03d4
--- /dev/null
+++ b/d13_input.txt
@@ -0,0 +1,2 @@
+1001796
+37,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x,41,x,x,x,x,x,x,x,x,x,457,x,x,x,x,x,x,x,x,x,x,x,x,13,17,x,x,x,x,x,x,x,x,23,x,x,x,x,x,29,x,431,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x,19
diff --git a/d13_output.txt b/d13_output.txt
new file mode 100644
index 0000000..76a4b45
--- /dev/null
+++ b/d13_output.txt
@@ -0,0 +1,2 @@
+261
+807435693182510