diff --git a/extra/queue-to-do/solution.py b/extra/queue-to-do/solution.py
new file mode 100644
index 0000000..f11590e
--- /dev/null
+++ b/extra/queue-to-do/solution.py
@@ -0,0 +1,16 @@
+def solution(start, length):
+    checksum = 0
+    for i in range(length):
+        base = start + length * i
+        for j in range(length - i):
+            checksum ^= base + j
+    return checksum
+
+tests = [
+        ([0, 3], 2),
+        ([17, 4], 14)
+        ]
+
+for i, o in tests:
+    result = solution(*i)
+    print (i, result == o, result, o)