import java.util.Scanner;

class Main{
    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);

        do{
            int a = scan.nextInt();
            int b = scan.nextInt();

            if (a == 0 && b == 0)
                break;
    
            if (a > b){
                int tmp = a;
                a = b;
                b = tmp;
            }

            System.out.println(a + " " + b);
        }while(true);
    }
}

    
/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