import java.util.Scanner;

/**
 * Created by labuser on 2016/04/19.
 */
public class Main {
    public static void main(String[] args) {
        new Main().run();
    }

    private void run() {

        int a, b;

        Scanner sc = new Scanner(System.in);
        while(true){
            String[] input = sc.nextLine().split(" ");
            a = Integer.parseInt(input[0]);
            b = Integer.parseInt(input[1]);
            if(a ==0 && b ==0){
                break;
            }
            System.out.println(Math.min(a,b)+" "+Math.max(a,b));
        }

    }
}
/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