diff --git a/E_1071_GreatestCommonDivisorofStrings.java b/E_1071_GreatestCommonDivisorofStrings.java
new file mode 100644
index 0000000..5f537c1
--- /dev/null
+++ b/E_1071_GreatestCommonDivisorofStrings.java
@@ -0,0 +1,18 @@
+class Solution {
+    public String gcdOfStrings(String str1, String str2) {
+        String ret= "";
+        if(!(str1+str2).equals(str2+str1)) return "";
+        else{
+            int sub = gcd(str1.length(),str2.length());
+            ret = str1.substring(0,sub);
+        }
+        return ret;
+    }
+
+    public int gcd(int len1, int len2){
+        if(len2==0)
+            return len1;
+        else
+            return gcd(len2,len1 % len2);
+    }
+}
\ No newline at end of file