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