From a77dd923b817ccec48abb995950c1e2dd78335ad Mon Sep 17 00:00:00 2001
From: kamyu <kamyu104@users.noreply.github.com>
Date: Sun, 23 Sep 2018 23:21:03 +0800
Subject: [PATCH] Update snakes-and-ladders.py

---
 Python/snakes-and-ladders.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Python/snakes-and-ladders.py b/Python/snakes-and-ladders.py
index bb5dfbd07..11c7c4c37 100644
--- a/Python/snakes-and-ladders.py
+++ b/Python/snakes-and-ladders.py
@@ -53,6 +53,9 @@
 # - The board square with number 1 has no snake or ladder.
 # - The board square with number N*N has no snake or ladder.
 
+import collections
+
+
 class Solution(object):
     def snakesAndLadders(self, board):
         """