import java.util.Scanner;

public class Main{
	public static void main(String[] args){
		Scanner in = new Scanner(System.in);
		int i,j;
		
		i=in.nextInt();
		j=in.nextInt();
		while(i!=0 || j!=0){
			if(i<j){
				System.out.println(i+" "+j);
			}else if(i>j){
				System.out.println(j+" "+i);	
			}else{
				System.out.println(i+" "+j);
			}
			i=in.nextInt();
			j=in.nextInt();
		}
		
		in.close();
	}
}
/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