import java.util.Scanner;

public class Main {

    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        for(int i = 0;i < 3000;++i){
            int a = sc.nextInt(),b = sc.nextInt();
            if(a == 0 && b == 0) break;
            System.out.printf("%d %d\n",a < b ? a : b,a < b ? b : a);
        }
        sc.close();
    }

}
/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