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