import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		int a,b,tmp;

		Scanner scan = new Scanner(System.in);

		while(true)
		{
		    a = scan.nextInt();
		    b = scan.nextInt();

		    tmp = a | b;

		    if(tmp == 0) break;

		    else if(b<a)
		    {
		    	tmp = a;
		    	a = b;
		    	b = tmp;
		    }

		    System.out.println(a + " " + b);
		}

	    scan.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