import java.util.Scanner;
public class Main
{
	public static void main(String args[])
	{
		int a, b;
		Scanner inp = new Scanner(System.in);
		while( true )
		{
			a = inp.nextInt();
			b = inp.nextInt();
			if(a == 0 && b == 0)
				break;
			else {
				if(a > b)
					System.out.println(b + " " + a);
				else
					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