Problem:
Swapping Two Numbers

Write a program which reads two integers x and y, and prints them in ascending order.

Input

The input consists of multiple datasets. Each dataset consists of two integers x and y separated by a single space.

The input ends with two 0 (when both x and y are zero). Your program should not process for these terminal symbols.

Output

For each dataset, print x and y in ascending order in a line. Put a single space between x and y.

Constraints

0 ≤ x, y ≤ 10000

the number of datasets ≤ 3000

Sample Input

3 2
2 2
5 3
0 0

Sample Output

2 3
2 2
3 5

Solution in JAVA (judge verdict: Wrong Answer)

import java.io.*;
import java.util.*;

class Main {
    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);

        for(int i = 1;;i++){
        
        int x = scan.nextInt();
            if(x == 0){
                break;
            }else {
                System.out.println("case " + i + ":" + " " + x);
            }
        }
    }
}