import java.util.Arrays;
import java.util.Scanner;


public class Main {
	
	public static void main(String args[]){
		Scanner sc = new Scanner(System.in);
		
		while(true){
			final long a = sc.nextLong();
			final long b = sc.nextLong();
			
			if(a == 0 && b == 0){
				break;
			}
			
			System.out.println(Math.min(a, b) + " " + Math.max(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