diff --git a/13/7 - Mystery Function b/13/7 - Mystery Function
new file mode 100644
index 0000000..316fe03
--- /dev/null
+++ b/13/7 - Mystery Function	
@@ -0,0 +1,4 @@
+def prod(L):
+   for i in L[1:]:
+      L[0] *= i
+   return L[0]