import java.util.*;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
       
        for(;true;){
            int x = sc.nextInt();
            int y = sc.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