import java.util.Scanner;
public class WhileObject4 {
   public static void main(String[]	args){
      int i = 0;
      SumString sumstr = new SumString("Hello there");
      SumString miles = new SumString("What's good");
      while (i++<4) {
         sumstr.addSum(i);
         sumstr.overWriteStr(i, "x");
         miles.overWriteStr(i, "g");
      }
      System.out.printf("sum = %d \"%s\"  %s", 
         sumstr.getSum(), 
         sumstr.getStr(),
         miles.getStr()
         );
      System.out.println();
   }
}


class SumString {
   int sum = 0;
   String str = "";
   
   SumString(String str) {
      this.str = str;
   }
   public int getSum(){
      return sum;
   }
   public String getStr(){
      return str;
   }
   public void setSum(int sum){
      this.sum = sum;
   }
   public void setStr(String str){
      this.str = str;
   }
   public void addSum(int i) {
      sum = sum + i;
   }
   /** overWrite index i with String sx */
   public void overWriteStr(int i, String sx){
      int len = str.length();
      if (i >= 0)
         str = str.substring(0,i-1)+ sx + str.substring(i,len);
   }
}