import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner kbScanner = new Scanner(System.in);
		int input1 = kbScanner.nextInt();
		int input2 = kbScanner.nextInt();
		
		while((input1 != 0) || (input2 != 0)){
			if(input1 > input2){
				int oki = input1;
				input1 = input2;
				input2 = oki;
			}
			System.out.println(input1 + " " + input2);
			input1 = kbScanner.nextInt();
			input2 = kbScanner.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