Crossing sequences

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

namespace _01_Crossing_sequences
{
    class Program
    {
        static void Main(string[] args)
        {
            var tribFirst = int.Parse(Console.ReadLine()); //[1...1000000]
            var tribSecond = int.Parse(Console.ReadLine()); //[1...1000000]
            var tribThird = int.Parse(Console.ReadLine()); //[1...1000000]
            var num = int.Parse(Console.ReadLine()); //[1...1000000]
            var spiralStep = int.Parse(Console.ReadLine()); //[1...1000000]

            int tribCurrent = tribFirst + tribSecond + tribThird;
            int spiralCurrent = num;
            int spiralStepMult = 1;
            int step = 1;

            while (tribCurrent <= 1000000 && spiralCurrent <= 1000000)
            {
                if (tribCurrent == spiralCurrent || spiralCurrent == tribFirst
                    || spiralCurrent == tribSecond || spiralCurrent == tribThird)
                {
                    Console.WriteLine(spiralCurrent);
                    break;
                }
                else if (tribCurrent < spiralCurrent)
                {
                    tribCurrent = tribFirst + tribSecond + tribThird;
                    tribFirst = tribSecond;
                    tribSecond = tribThird;
                    tribThird = tribCurrent;
                }
                else
                {
                    spiralCurrent += spiralStepMult * spiralStep;
                    if (step % 2 == 0) spiralStepMult++;
                    step++;
                }
            }

            if (tribCurrent > 1000000 || spiralCurrent > 1000000) Console.WriteLine("No");
        }
    }
}