import java.util.Scanner;

public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int i=1;
		while(true){
			int x=sc.nextInt();
			int y=sc.nextInt();
			if(x==0&&y==0)break;
			if(x<y){
				System.out.println(x+" "+y);
			}else{
				System.out.println(y+" "+x);
			}
			i++;
		}
	}
}
/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