Fault in given program

Sir
What is the fault in this program??

import java.util.*;
public class Main {
public static void main(String args[]) {
Scanner obj = new Scanner(System.in);

    while(true){
        char ch = obj.next().charAt(0);

    if(ch=='+' || ch=='-' || ch=='*' || ch=='/' || ch=='%'){
        int n1 = obj.nextInt();
        int n2 = obj.nextInt();
        if(n1>0 && n1<100000000){
            if(n2>0 && n2<100000000){
                int res = 0;
                switch(ch){
                    case '+':
                    res = n1+n2;
                    break;
                    case '-':
                    res = n1-n2;
                    break;
                    case '*':
                    res = n1*n2;
                    break;
                    case '/':
                    res = n1/n2;
                    break;
                    case '%':
                    res = n1%n2;
                    break;
                }
                System.out.println(res);
                System.exit(0);
            }
        }
    }else if(ch=='x' || ch=='X'){
        System.exit(0);
    }else{
        System.out.println("Invalid operation. Try again.");
    }
    }
}

}

You need to remove this statement after printing the result. You program should exit only if x or X is encountered.