import java.util.Scanner;

public class Main
{
	public static void main(String[] args)
	{
		Scanner scanner = new Scanner(System.in);
		for(int i=1;; i++)
		{		
			int a = scanner.nextInt();
			int b = scanner.nextInt();
			
			if(a==0 && b==0)
			{
				break;
			}
			else if(a > b)
			{
				int buf = a;
				a = b;
				b = buf;
				
			}
			System.out.println(a+" "+b);
		}
	}
}
/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