import java.util.Scanner;

public class Main {
	public static void main(String args[]){
		Scanner scan = new Scanner(System.in);


		while(true){
			int x = scan.nextInt();
			int y = scan.nextInt();

			if(x==0 & y==0){break;}

			String result = x < y ? x + " " + y : y + " " + x;

			System.out.println(result);

		}

		scan.close();
	}
}
/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