changed BigOFunc argument from size_t to int
diff --git a/README.md b/README.md
index f34e887..e30052d 100644
--- a/README.md
+++ b/README.md
@@ -147,7 +147,7 @@
 
 ```c++
 BENCHMARK(BM_StringCompare)->RangeMultiplier(2)
-    ->Range(1<<10, 1<<18)->Complexity([](size_t n)->double{return n; });
+    ->Range(1<<10, 1<<18)->Complexity([](int n)->double{return n; });
 ```
 
 ### Templated benchmarks