Interfaces Hackerrank

using System;
public interface AdvancedArithmetic{
    int divisorSum(int n);
}

public class Calculator : AdvancedArithmetic
{
    public int divisorSum(int n)
    {
        int sum = 0;
        for(int i = n;i>0;i--){
            if(n % i == 0){
                sum += i;
            }
        }
        return sum;
    }
}

class Solution{
    static void Main(string[] args){
        int n = Int32.Parse(Console.ReadLine());
        AdvancedArithmetic myCalculator = new Calculator();
        int sum = myCalculator.divisorSum(n);
        Console.WriteLine("I implemented: AdvancedArithmetic\n" + sum);
    }
}