using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication30
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("input yor first split char: ");
            ConsoleKeyInfo usrKey1 = Console.ReadKey();
            Console.WriteLine("input yor second split char: ");
            ConsoleKeyInfo usrKey2 = Console.ReadKey();
            Console.WriteLine();

            int count = 0;
            Console.WriteLine("input your string: ");
            string str = Console.ReadLine();

            count = str.LastIndexOf(usrKey2.KeyChar) - str.IndexOf(usrKey1.KeyChar) - 1;
            if (str.LastIndexOf(usrKey2.KeyChar) == (-1) || str.IndexOf(usrKey1.KeyChar) == (-1))
                Console.WriteLine("this chars is out of string");
            //for (int i = str.IndexOf(usrKey1.KeyChar) + 1; i < str.LastIndexOf(usrKey2.KeyChar); i++)
            //    count++;
            Console.WriteLine(count);
            Console.ReadLine();
        }
    }
}