comefrom: <awangdev>43. Multiply Strings_2.java
code: private int toInt(String s, int x) {
  
          return s.charAt(x) - '0';
      }
masked: private int sample_funcname ( String var_1 , int var_2 ) {
    return var_1 . charAt ( var_2 ) - '0' ;
  }
  