import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        for(int i = 0; i < 3000; i++) {
            int x = scanner.nextInt();
            int y = scanner.nextInt();
            if (x == 0 && y == 0) {
                break;
            }
            if (x < y) {
                System.out.println(x + " " + y);
            } else {
                System.out.println(y + " " + x);
            }
        }
    }
}


/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