import java.util.*;
public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int i = 1;
		while(i == 1){
			int X = sc.nextInt();
			int Y = sc.nextInt();
			if(X > Y){
				int tmp;
				tmp = X;
				X = Y;
				Y = tmp;
			}
			if(X == 0 && Y == 0)
				break;
			else
				System.out.println(X +" "+ Y);
		}
		sc.close();
	}
}
/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