import java.io.IOException;
import java.util.Scanner;

class Main {

	public static void main(String[] args) throws IOException {

		Scanner scan = new Scanner(System.in);

		int num1 = 1, num2 = 1;


		while (true) {

			num1 = scan.nextInt();
			num2 = scan.nextInt();

			if((num1 ==0) && (num2 ==0)){
				break;
			}


			if(num1 > num2){
				System.out.println(num2+" "+num1);
			}else {
				System.out.println(num1+" "+num2);
			}
		}

	}

}
/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