added error code to div by 0

src/com/company/Calc.java

@@ -34,6 +34,7 @@ public class Calc {
         int div2 = Integer.parseInt(num2);
         if (div2 == 0 || div1 == 0){
             print("cant divide by zero");
+            print("error code:");
             return -1;
         }
         return div1 / div2;