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.*;

public class Main {
	public static void main(String args[]){
		Scanner scan = new Scanner(System.in);
		StringBuilder sb = new StringBuilder();
		
		int x,y;
		List<String> list = new ArrayList<String>();
		
		boolean flg1,flg2;
		flg1 =false;
		flg2 = false;
		
		//??????0??§????????????
		while(true){
			x = scan.nextInt();
			y = scan.nextInt();
			//x???0?????´??????true?????????
			if (x == 0){flg1= true;}
			//y???0?????´??????true?????????
			if (y == 0){flg2 = true;}
			//x??¨y???0?????´????????????????????????
			if ((flg1 == true) & (flg2 == true)){break;}
			
			//????????????????????????????????????????????????????????????
			list.add(Integer.toString(x));
			list.add(Integer.toString(y));
			
			Collections.sort(list);
			
			sb.append(Integer.parseInt(list.get(0)));
			sb.append(" ");
			sb.append(Integer.parseInt(list.get(1)));
			sb.append("\n");
			
			//???????????????????????????
			list.clear();
			
			//x??¨y????????????????????????0?????´????????????????¶??¶????????????????flg???false?????????
			flg1 = false;
			flg2 = false;
			
		}
		
		System.out.print(new String(sb));
		
		
	}
}