
import java.util.Scanner;
public class Main{


	public static void main(String[] args) {

		Scanner sc=new Scanner(System.in);
		
		int a,b;
		a=sc.nextInt();
		b=sc.nextInt();
		
		while(a!=0 || b!=0){
			
			System.out.println(b>a?a+" " +b:b+" "+a);
			a=sc.nextInt();
			b=sc.nextInt();
		}
		
	}

}
/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