import java.util.Scanner;

class Main {

	public static void main(String[] args) {

		Scanner scan = new Scanner(System.in);

		for(;;){
			int num1 = scan.nextInt();
			int num2 = scan.nextInt();

			if(num1 == 0 && num2 ==0){
				scan.close();
				break;
			}
			else{
				if(num1 <= num2){
					System.out.println(num1 + " " + num2);
				}
				else if(num2 < num1){
					System.out.println(num2 + " " + num1);
				}
			}
		}
	}

}
/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