import java.util.Scanner;
import java.util.Arrays;

class Main{
    public static void main(String[] args){
        Scanner input = new Scanner(System.in);
        while(true){
            String str = input.nextLine();
            String[] str1 = str.split(" ");
            int x = Integer.parseInt(str1[0]);
            int y = Integer.parseInt(str1[1]);
            if(x==0 && y==0){
                break;
            }else{
                int[] output = {x,y};
                Arrays.sort(output);
                System.out.println(output[0] + " " + output[1]);
            }
            

        }
    }
}

/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