diff --git a/triangularSum.py b/triangularSum.py
new file mode 100644
index 000000000000..d1daa321900d
--- /dev/null
+++ b/triangularSum.py
@@ -0,0 +1,9 @@
+class Solution:
+    def triangularSum(self, nums):
+        current = nums[:]
+        while len(current) > 1:
+            new_nums = []
+            for i in range(len(current) - 1):
+                new_nums.append((current[i] + current[i + 1]) % 10)
+            current = new_nums
+        return current[0]