SoftUni cake

using System;

namespace _18_11_2019_cake
{
    class Program
    {
        static void Main()
        {

            int cakeWidth = int.Parse(Console.ReadLine());
            int cakeLength = int.Parse(Console.ReadLine());
            int cakeSize = cakeLength * cakeWidth;
            int cakeNumber = 0;
            string input = "";
            int piecesLeft = 0;
            int piecesNeed = 0;

            while (cakeSize > cakeNumber)
            {
                input = Console.ReadLine();

                if (input == "STOP")
                {
                    piecesLeft = cakeSize - cakeNumber;
                    Console.WriteLine($"{piecesLeft} pieces are left.");
                    return;
                }
                else cakeNumber += int.Parse(input);

            }
            if (cakeNumber >= cakeSize)
            {
                piecesNeed = cakeNumber - cakeSize;
                Console.WriteLine($"No more cake left! You need {piecesNeed} pieces more.");
            }
        }
    }
}