import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        int intx, inty;
        Scanner sc = new Scanner(System.in);
        while(sc.hasNext()){
            String[] str = sc.nextLine().split(" ");
            intx = Integer.parseInt(str[0]);
            inty = Integer.parseInt(str[1]);

            if( intx == 0 && inty == 0) break;
            else if(intx < inty) System.out.println(intx + " " + inty);
            else System.out.println(inty + " " + intx);
        }
        sc.close();
    }
}
/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