diff --git a/STL.cpp b/STL.cpp
new file mode 100644
index 0000000..6e05de3
--- /dev/null
+++ b/STL.cpp
@@ -0,0 +1,38 @@
+#include <cmath>
+#include <cstdio>
+#include <vector>
+#include <iostream>
+#include <set>
+#include <map>
+#include <algorithm>
+using namespace std;
+
+
+int main() {
+    int n;
+    cin >> n;
+    
+    map<string, int> m;
+    
+    while (n--) {
+        int t;
+        cin >> t;
+        
+        string s;
+        cin >> s;
+        
+        if (t == 1) {
+            int a;
+            cin >> a;
+            
+            m[s] += a;
+        } else if (t == 2) {
+            m[s] = 0;
+        } else {
+            cout << m[s] << "\n";
+        }
+    }
+    
+    return 0;
+}
+