import java.util.Scanner;

public class Main{
    public static void main(String argv[])
    {
	Scanner scan = new Scanner(System.in);
	int x,y;

	while(true)
	    {
		x = scan.nextInt();
		y = scan.nextInt();
		if( x == 0 && y == 0 )
		    break;
		else if( x <= y)
		    System.out.println(x+" "+y);
		else if( x > y )
		    System.out.println(y+" "+x);
	    }
    }
}
/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