import java.util.Scanner;

class Main {
    public static void main(String[] args) throws Exception{
        Scanner sc = new Scanner(System.in);
        while(true){
        int x = sc.nextInt();
        int y = sc.nextInt();
        if(x == 0 && y == 0){
            break;
        }
        System.out.println(Math.min(x,y)+" "+Math.max(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