import java.util.Scanner;

class Main {
	public static void main(String args[]) {
		Scanner scan = new Scanner(System.in);
		
		while (true) {
			int x = Integer.parseInt(scan.next());
			int y = Integer.parseInt(scan.next());
			
			if (x == 0 && y == 0) {
				break;
			}
			
			if (x > y) {
				int tmp = x;
				x = y;
				y = tmp;
			}
			
			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