her's my cod! Please help!
using System;

namespace ConsoleApplication1
{
    class Program1563
    {
        static void Main()
        {
            int n = int.Parse(Console.ReadLine());
            string str;
            string[] strl = new string[n];
            int s = -1;
            for (int i = 0; i < n; i++)
            {
                str = Console.ReadLine();
                strl[i] = str;
                Console.WriteLine("i="+i);
                for (int j = 0; j < i; j++)
                {
                    if (str == strl[j])
                        s++;
                }
            }

            Console.WriteLine(s);
                    Console.ReadLine();
        }
    }
}