diff --git a/Note.md b/Note.md
index 83ed223..8fd71b9 100644
--- a/Note.md
+++ b/Note.md
@@ -10,6 +10,7 @@
 - C++：
   ```c++
   #include<iostream>
+  using namespace std;
   int main(){
     cout << "Hello world!" << endl;
     return 0;