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.util.ArrayList;
import java.util.Scanner;

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

		ArrayList<Integer> numList1 = new ArrayList<Integer>();
		ArrayList<Integer> numList2 = new ArrayList<Integer>();

		while (true) {
			String[] lines = sc.nextLine().split(" ");
			int num1 = Integer.parseInt(lines[0]);
			int num2 = Integer.parseInt(lines[1]);
			if(num1 != 0 && num2 != 0) {
				numList1.add(num1);
				numList2.add(num2);
			} else {
				break;
			}
		}
		for(int i = 0;i < numList1.size();i++) {
			if(numList1.get(i) > numList2.get(i)) {
				int x = numList1.get(i);
				numList1.set(i, numList2.get(i));
				numList2.set(i, x);
			}
			System.out.println(numList1.get(i) + " " + numList2.get(i));
		}
		sc.close();
	}
}