import java.util.*;
class Main{
    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);
        while(true){
            int a = scan.nextInt();
            int b = scan.nextInt();
            if(a == 0 && b == 0) break;
            if(a < b) System.out.println(a + " " + b);
            else System.out.println(b + " " + a);
        }
    }
}
/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