Write a C# Sharp program to check whether a given string starts with "F" or ends with "B". If the string starts with "F" return "Fizz" and return "Buzz" if it ends with "B" If the string starts with "F" and ends with "B" return "FizzBuzz". In other cases return the original string

using System;
using System.Linq;
namespace exercises
{
   class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine(test("FizzBuzz"));
            Console.WriteLine(test("Fizz"));
            Console.WriteLine(test("Buzz"));
            Console.WriteLine(test("Founder"));
            Console.ReadLine();
        }
       public static string test(string str)
        {
            if (str.StartsWith("F") && str.EndsWith("B"))
            {
                return "FizzBuzz";
            }
            else if (str.StartsWith("F"))
            {
                return "Fizz";
            }
            else if (str.EndsWith("B"))
            {
                return "Buzz";
            }
            else
            {
                return str;
            }
        }
    }
}