import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		
		Scanner s = new Scanner(System.in);
		
		
		while(true){
			 
			 int x = Integer.parseInt(s.next());
			 int y = Integer.parseInt(s.next());
			 
			 if(x==0 && y==0){
				 break;
			 }
			 if(x<y){
				 System.out.println(x+" "+y);
			 }else{
				 System.out.println(y+" "+x);
			 }	 

		}
	}

}
/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