import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int tmp;
        while(true){
            int x = sc.nextInt();
            int y = sc.nextInt();
            if ( x == 0 && y == 0 ) break;
            if (x > y){
            	tmp = x;
            	x = y;
            	y = tmp;
            }
            System.out.println(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