import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		for(int i = 1 ; i <= 10000; i++) {
			int x = sc.nextInt();
			int y = sc.nextInt();
			int t = 0;
			if(x > y) {
				t = x;
				x = y;
				y = t;
			}
			if(x == 0 && y == 0) {
				break;
			}
			System.out.println(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