diff --git a/epi_judge_python_solutions/minimum_waiting_time.py b/epi_judge_python_solutions/minimum_waiting_time.py
index b0da6102b..9c5d3d245 100644
--- a/epi_judge_python_solutions/minimum_waiting_time.py
+++ b/epi_judge_python_solutions/minimum_waiting_time.py
@@ -2,16 +2,14 @@
 
 from test_framework import generic_test
 
+import itertools
+
 
 def minimum_total_waiting_time(service_times: List[int]) -> int:
 
     # Sort the service times in increasing order.
     service_times.sort()
-    total_waiting_time = 0
-    for i, service_time in enumerate(service_times):
-        num_remaining_queries = len(service_times) - (i + 1)
-        total_waiting_time += service_time * num_remaining_queries
-    return total_waiting_time
+    return sum(itertools.accumulate(service_times[:-1]))
 
 
 def minimum_total_waiting_time_pythonic(service_times):