import java.util.Scanner;
class Main {
	public void aa() {
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		int y = sc.nextInt();
		while(x != 0 || y != 0) {
			if(x < y) {
				System.out.println(x + " " + y);
			} else {
				System.out.println(y + " " + x);
			}
			x = sc.nextInt();
			y = sc.nextInt();
		}
	}
	public static void main(String[] args) {
		new Main().aa();
	}
}
/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