import java.util.Scanner;

public class Main {
	public static void main(String args[]){
		Scanner scan = new Scanner(System.in); 
		int x, y;
		
		for(int i = 1; i <= 10000; i++){
			x = scan.nextInt();
			y = scan.nextInt();
			
			if(x == 0 && y == 0){
				break;
			}
			
			if(x > y){
				int a;
				a = x;
				x = y;
				y = a;
			}
			
			System.out.println(x + " " + y);
		}
	
	}

}
/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