import java.util.Scanner;

public class Main {

  private static int x;
  private static int y;

  public static void main(String[] args) {
    Scanner stdIn = new Scanner(System.in);
    for (int i = 0; i < 3000 ; i++ ) {
      x = stdIn.nextInt();
      y = stdIn.nextInt();
      if (x == 0 && y == 0) {
        break;
      } else {
        if (x <= y) {
          System.out.println(x + " " + y);
        } else {
          System.out.println(y + " " + x);
        }
      }
    }
  }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz