import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int a,b;
		for(int i=1;;i++){
			a = sc.nextInt();
			b = sc.nextInt();
			if(a==0&&b==0)break;
			if(a<b)
				System.out.println(a+" "+b);
			else
				System.out.println(b+" "+a);
		}
	}

}
/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