import java.util.Scanner;
public class Main {
	public static void main(String[] args){
		Scanner scan = new Scanner(System.in);
		int z= 0;
		for(int a=1;a>0;a++){
			int x = scan.nextInt();
			int y = scan.nextInt();
			if(x==0 && y==0){
				break;
			}
			if(x>y){
				z = x;
				x = y;
				y = z;
			}
			if(x<=y){
				System.out.println(x +" "+ y);
			}
		}
	}
}
/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