import java.util.Scanner;

class Main{
    public static void main(String[] a){
    	int x, y ,tmp;
    	Scanner in = new Scanner(System.in);
      while (true){
      	x = in.nextInt();
      	y = in.nextInt();
      	if(x == 0 && y == 0) break;
      	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