import java.util.Scanner;
	class Main{

		public static void main(String[] args){
	Scanner sc=new Scanner(System.in);
int x;
int y;
int hantei =9;
for(;hantei!=0;){
	x=sc.nextInt();
	y=sc.nextInt();
	
	if(x==0){
		if(y==0){
		System.exit(0);	
		}
	}
	if(x<=y){
		System.out.println(x + " "+y);
	}else if(y<x){
		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