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)){
			if(a >= b){
				System.out.println(b + " " + a);
			}else{
				System.out.println(a + " " + b);
			}
			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