diff --git a/README.md b/README.md
index cd92c21..2eebc0d 100644
--- a/README.md
+++ b/README.md
@@ -233,6 +233,7 @@ You can contribute to any open source project hosted on Github.com and contribut
 │   │   ├── rod_cutting_prob.cpp
 │   │   ├── sub_matrix_with_all_1s.cpp
 │   │   └── two_sum.cpp
+│   │   └── 3Sum.cpp
 │   ├── java
 │   │   ├── coin_change.java
 │   │   └── queInfo.md