ConvertMetric/MetricConvert

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

namespace ConvertMetric
{
    class Program
    {
        static void Main(string[] args)
        {
            var sum = double.Parse(Console.ReadLine());
            string vxod = Console.ReadLine();
            string izxod = Console.ReadLine();
            double mm = 1000;
            double m = 1;
            double cm = 100;
            double mi = 0.000621371192;
            double inch = 39.3700787;
            double km = 0.001;
            double ft = 3.2808399;
            double yd = 1.0936133;
            {
                if (vxod == "mm") { sum = sum / mm; }
                else if (vxod == "m") { sum = sum / m; }
                else if (vxod == "cm") { sum = sum / cm; }
                else if (vxod == "mi") { sum = sum / mi; }
                else if (vxod == "in") { sum = sum / inch; }
                else if (vxod == "km") { sum = sum / km; }
                else if (vxod == "ft") { sum = sum / ft; }
                else if (vxod == "yd") { sum = sum / yd; }

                if (izxod == "mm") { sum = sum * mm; }
                else if (izxod == "m") { sum = sum * m; }
                else if (izxod == "cm") { sum = sum * cm; }
                else if (izxod == "mi") { sum = sum * mi; }
                else if (izxod == "in") { sum = sum * inch; }
                else if (izxod == "km") { sum = sum * km; }
                else if (izxod == "ft") { sum = sum * ft; }
                else if (izxod == "yd") { sum = sum * yd; }

                Console.WriteLine(sum);

            }
        }
    }
}