using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

​

namespace ConsoleApp2

{

    public class Program

    {

        //Zadacha 3

        /* Напишете програма, която открива колко пъти  се 

          съдържа подниза "e" в текста:

​

            We are living in a yellow submarine. We don't have anything else. 

            Inside the submarine is very tight. So we are drinking all the day. 

            We will move out of it in 5 days.

​

           */

        public static void Main(string[] args)

        {

            string text = "We are living in a yellow submarine. We don't have " +

                "anything else. Inside the submarine is very tight. So we are" +

                " drinking all the day.We will move out of it in 5 days.";

​

            text = text.ToLower();

            string keyWord = "e";

            int index = text.IndexOf(keyWord);

            int count = 0;

​

            while(index != -1)

            {

                count++;

                index = text.IndexOf(keyWord, index + keyWord.Length);

            }

​

            Console.WriteLine(count);

        }

    }

}

​