import java.util.Scanner;

class Main {

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