import java.util.Scanner;

public class Main {
	void run(){
		Scanner s = new Scanner(System.in);
	    int x, y ,min;
	    for(;;) {
	    	x = s.nextInt();
	 	    y = s.nextInt();
	    	if(x == 0 && y == 0) break;
	    	else if(x < y) System.out.println(x + " " + y);
	    	else  System.out.println(y + " " + x);
	    }
	    
	}
	public static void main(String[] args) {
		
		new Main().run();
		
	}
}
/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