import java.util.Scanner;

public class Main {

  public static void main(String[] args) {
    Scanner stdin = new Scanner(System.in);
    while (true) {
      int x = stdin.nextInt();
      int y = stdin.nextInt();
      if (x == 0 && y == 0) {
        break;
      } else if (x > y) {
        System.out.printf("%d %d%n", y, x);
      } else {
        System.out.printf("%d %d%n", x, y);
      }
    }
  }

}
/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