diff --git a/intro-to-algorithms/ch01.py b/intro-to-algorithms/ch01.py
index aced933..38e8f41 100644
--- a/intro-to-algorithms/ch01.py
+++ b/intro-to-algorithms/ch01.py
@@ -2,7 +2,7 @@ from __future__ import print_function
 
 import os
 import random
-import unittest
+import timeit
 
 
 DEBUG = os.environ.get('DEBUG') == '1'
@@ -32,26 +32,26 @@ def insertion_sort(arr):
     return arr
 
 
-class TestStuff(unittest.TestCase):
+def main():
+    for power in range(1, 5):
+        to_sort = list(range(10 ** power))
+        to_sort_sorted = to_sort[:]
+        to_sort_reversed = list(reversed(to_sort[:]))
 
-    def test_insertion_sort_small(self):
-        self.assertEqual(
-            [1, 2, 3, 4, 5, 6],
-            insertion_sort([5, 2, 4, 6, 1, 3])
-        )
+        for i in range(3):
+            random.shuffle(to_sort)
 
-    def test_insertion_sort_large(self):
-        inlist = range(1000)
-        listcopy = inlist[:]
-        random.shuffle(inlist)
-        random.shuffle(inlist)
-        self.assertEqual(listcopy, insertion_sort(inlist))
+        for arr, desc in (
+            (to_sort_sorted, 'sorted'),
+            (to_sort, 'shuffled'),
+            (to_sort_reversed, 'reversed')):
 
-    def test_insertion_sort_large_reversed(self):
-        inlist = range(1000)
-        listcopy = inlist[:]
-        self.assertEqual(listcopy, insertion_sort(list(reversed(inlist))))
+            timing = timeit.timeit(
+                lambda: insertion_sort(arr),
+                number=10
+            )
+            print('{} {}: {}'.format(10 ** power, desc, timing))
 
 
 if __name__ == '__main__':
-    unittest.main()
+    main()