import java.util.*;
class Main{
	static Scanner s = new Scanner(System.in);
	public static void main(String[] args) {
		int in1,in2;
		while(true) {
			in1 = Integer.parseInt(s.next());
			in2 = Integer.parseInt(s.next());
			if((in1|in2)==0)
				return;
			if(in1<=in2)
				System.out.printf("%d %d\n",in1,in2);
			else
				System.out.printf("%d %d\n",in2,in1);
		}
	}
}
/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