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

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            {
                string metin;
                Console.Write("Enter letters and zero : ");
                metin = Console.ReadLine();
                int sayac = 0;
                for (int i = 0; i <= metin.Length; i++)
                {
                    if (metin[i] == '0')
                    {
                        sayac++;
                    }
                }
                Console.WriteLine("Girilen Metindeki 0 adeti : {0}", sayac);
                Console.ReadKey();
            }
        }
    }
}