diff --git a/Number Theory/string_mod_int.cpp b/Number Theory/string_mod_int.cpp
new file mode 100644
index 0000000..539d970
--- /dev/null
+++ b/Number Theory/string_mod_int.cpp	
@@ -0,0 +1,11 @@
+int operator%(string& a , int b){
+
+    int sz = (int)a.size();
+    int val = 0;
+    for(int idx = 0 ; idx < sz ; idx++ ){
+        val = 10*val + (a[idx]-'0');
+        val %= b;
+    }
+
+    return val;
+}
\ No newline at end of file