import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO ?????????????????????????????????????????????
		
		Scanner sc = new Scanner(System.in);
		int x=Integer.parseInt(sc.next());
		int y=Integer.parseInt(sc.next());
		while(x!=0 || y!=0){
			if(x<y) System.out.println(x+" "+y);
			else System.out.println(y+" "+x);
			x=Integer.parseInt(sc.next());
			y=Integer.parseInt(sc.next());
		}

	}

}
/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