Exam 8. Student Cables

namespace _2.StudentCables
{
    using System;

    public class StudentCables
    {
        public static void Main(string[] args)
        {
            checked
            {
                int numCables = int.Parse(Console.ReadLine());

                int cableLength = 0;
                int countCables = 0;
                for (int i = 0; i < numCables; i++)
                {
                    int cable = int.Parse(Console.ReadLine());
                    string measure = Console.ReadLine();
                    if (measure == "meters")
                    {
                        cable *= 100;
                    }

                    if (cable >= 20)
                    {
                        cableLength += cable;
                        countCables++;
                    }
                }

                if (countCables > 1)
                {
                    cableLength -= 3 * (countCables - 1);
                }

                int studentCables = cableLength / 504;
                int remainCable = cableLength % 504;

                Console.WriteLine(studentCables);
                Console.WriteLine(remainCable);
            }
        }
    }
}