import java.util.Scanner;
public class Main {
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
		int a,b,tmp;
		for(;;){
		a = scan.nextInt();
		b = scan.nextInt();
		if(a >= b){
			tmp = a;
			a = b;
			b = tmp;
		}
		
		if (a == 0 && b == 0)
			break;
		System.out.println(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