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: Accepted)

import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		StringBuilder output = new StringBuilder();
		Scanner scan = new Scanner(System.in);
		while(true) {
			int a = scan.nextInt();
			int b = scan.nextInt();
			if (a == 0 && b == 0)
				break;
			if (a <= b) {
				output.append(a).append(" ").append(b).append('\n');
			} else {
				output.append(b).append(" ").append(a).append('\n');
			}
		}
		System.out.print(output);
	}
}