Salt and papper

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

namespace Salt_and_Pepper
{
    class Program
    {
        static void Main(string[] args)
        {
            var dishes = ulong.Parse(Console.ReadLine());
            string commands = Console.ReadLine();
            while (commands != "end")
            {
                string[] words = commands.Split(' ');
                var spice = words[0];
                var step =int.Parse(words[1]);

                if (spice == "pepper")
                {
                    for (int i = 0; i < 64; i+=step)
                    {
                        dishes |= (ulong)1 << i;
                    }
                }
                if (spice == "salt")
                {
                    for (int i = 0; i < 64; i+=step)
                    {
                        dishes &= ~((ulong)1 << i);
                    }
                }
                commands = Console.ReadLine();
            }
            Console.WriteLine(dishes);
        }
    }
}