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.*;

class Main{
  public static void main(String[] args) throws IOException{
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringBuilder sb = new StringBuilder();

    int x, y;

    while (true){
      String line = br.readLine();
      String[] data = line.split(" ");
      x = Integer.parseInt(data[0]);
      y = Integer.parseInt(data[1]);
      if (x == 0 && y == 0) {break;}
      sb.append(data[1] + " ").append(data[0]).append("\n");
    }
    System.out.println(sb);
  }
}