Best and easy programs in C#

Q:- Write a program in C# that take a sentence as input, and show the number of "a" used in the sentence???
Ans;-  using System;
using System.Collections.Generic;
using System.Text;

namespace codeforevenorodd
{
    class Program
    {
        static void Main(string[] args)
        {
            string name;
            int counter = 0;
            int i;
            name = Console.ReadLine();
            for ( i=0; i <name.Length; i++)
            {
                if (name[i] == 'a')
                {
                    counter++;
                }
            }
                Console.WriteLine(counter);
                Console.ReadLine();
            }
           

        }
    }