import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

class Main {

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

		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		while(true){
			String str = br.readLine();
			String strArray[] = str.split(" ", 0);
			int num1 = Integer.parseInt(strArray[0]);
			int num2 = Integer.parseInt(strArray[1]);

			if(num1 == 0 && num2 ==0){
				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