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

namespace MetricConverter
{
    class MetricConverter
    {
        static void Main(string[] args)
        {
            Console.Write("Enter a number: ");
            double number = double.Parse(Console.ReadLine());
            Console.Write("Enter input unit: ");
            string input = Console.ReadLine().ToLower();
            Console.Write("Enter output unit: ");
            string output = Console.ReadLine().ToLower();
            switch (input)
            {
                case "mm":
                    if (output == "mm")
                    {
                        Console.WriteLine(number + " " + output);
                    }
                    else
                    {
                        switch (output)
                        {
                            case "cm":
                                Console.WriteLine(number / 10 + " " + output); break;
                            case "mi":
                                Console.WriteLine((number * 6.21371192E-7) + " " + output); break;
                            case "in":
                                Console.WriteLine((number * 39.3700787E-3) + " " + output); break;
                            case "km":
                                Console.WriteLine((number * 1E-6) + " " + output); break;
                            case "ft":
                                Console.WriteLine((number * 3.2808399E-3) + " " + output); break;
                            case "yd":
                                Console.WriteLine((number * 1.0936133E-3) + " " + output); break;
                            case "m":
                                Console.WriteLine(number * .001 + " " + output); break;
                        }
                    };
                    break;
                case "cm":
                    if (output == "cm")
                    {
                        Console.WriteLine(number + " " + output);
                    }
                    else
                    {
                        switch (output)
                        {
                            case "mm":
                                Console.WriteLine(number * 10 + " " + output); break;
                            case "mi":
                                Console.WriteLine((number * 6.21371192E-6) + " " + output); break;
                            case "in":
                                Console.WriteLine((number * 39.3700787E-2) + " " + output); break;
                            case "km":
                                Console.WriteLine((number * 1E-5) + " " + output); break;
                            case "ft":
                                Console.WriteLine((number * 3.2808399E-2) + " " + output); break;
                            case "yd":
                                Console.WriteLine((number * 1.0936133E-2) + " " + output); break;
                            case "m":
                                Console.WriteLine(number * .01 + " " + output); break;
                        }
                    };
                    break;
                case "mi":
                    if (output == "mi")
                    {
                        Console.WriteLine(number + " " + output);
                    }
                    else
                    {
                        switch (output)
                        {
                            case "cm":
                                Console.WriteLine(number * (100 / 621.371192E-6) + " " + output); break;
                            case "mm":
                                Console.WriteLine(number * (1000 / 621.371192E-6) + " " + output); break;
                            case "in":
                                Console.WriteLine(number * (39.3700787 / 621.371192E-6) + " " + output); break;
                            case "km":
                                Console.WriteLine(number * (0.001 / 621.371192E-6) + " " + output); break;
                            case "ft":
                                Console.WriteLine(number * (3.2808399 / 621.371192E-6) + " " + output); break;
                            case "yd":
                                Console.WriteLine(number * (1.0936133 / 621.371192E-6) + " " + output); break;
                            case "m":
                                Console.WriteLine(number * (1/ 621.371192E-6) + " " + output); break;
                        }
                    };
                    break;
                case "in":
                    if (output == "in")
                    {
                        Console.WriteLine(number + " " + output);
                    }
                    else
                    {
                        switch (output)
                        {
                            case "cm":
                                Console.WriteLine(number * 2.54 + " " + output); break;
                            case "mm":
                                Console.WriteLine((number * 25.4) + " " + output); break;
                            case "km":
                                Console.WriteLine(number * (0.001 / 39.3700787) + " " + output); break;
                            case "mi":
                                Console.WriteLine(number * (621.371192E-6 / 39.3700787) + " " + output); break;
                            case "ft":
                                Console.WriteLine(number * (3.2808399 / 39.3700787) + " " + output); break;
                            case "yd":
                                Console.WriteLine(number * (1.0936133 / 39.3700787) + " " + output); break;
                            case "m":
                                Console.WriteLine(number * (1 / 39.3700787) + " " + output); break;
                        }
                    };
                    break;
                case "km":
                    if (output == "km")
                    {
                        Console.WriteLine(number + " " + output);
                    }
                    else
                    {
                        switch (output)
                        {
                            case "cm":
                                Console.WriteLine(number * 1E+5 + " " + output); break;
                            case "mi":
                                Console.WriteLine(number * 0.621371192 + " " + output); break;
                            case "in":
                                Console.WriteLine((number * 39370.0787) + " " + output); break;
                            case "mm":
                                Console.WriteLine((number * 1E+6) + " " + output); break;
                            case "ft":
                                Console.WriteLine((number * 3280.8399) + " " + output); break;
                            case "yd":
                                Console.WriteLine((number * 1093.6133) + " " + output); break;
                            case "m":
                                Console.WriteLine(number * 1000 + " " + output); break;
                        }
                    };
                    break;
                case "ft":
                    if (output == "ft")
                    {
                        Console.WriteLine(number + " " + output);
                    }
                    else
                    {
                        switch (output)
                        {
                            case "mm":
                                Console.WriteLine(number * (1000 / 3.2808399)+ " " + output); break;
                            case "mi":
                                Console.WriteLine(number * (6.21371192E-4 / 3.2808399) + " " + output); break;
                            case "in":
                                Console.WriteLine(number * ( 39.3700787 / 3.2808399) + " " + output); break;
                            case "km":
                                Console.WriteLine(number * (0.001 / 3.2808399) + " " + output); break;
                            case "cm":
                                Console.WriteLine(number * (100 / 3.2808399) + " " + output); break;
                            case "yd":
                                Console.WriteLine(number * (1.0936133 / 3.2808399) + " " + output); break;
                            case "m":
                                Console.WriteLine(number * (1 / 3.2808399) + " " + output); break;
                        }
                    };
                    break;
                case "yd":
                    if (output == "yd")
                    {
                        Console.WriteLine(number + " " + output);
                    }
                    else
                    {
                        switch (output)
                        {
                            case "cm":
                                Console.WriteLine(number * (100 / 1.0936133) + " " + output); break;
                            case "mm":
                                Console.WriteLine(number * (1000 / 1.0936133) + " " + output); break;
                            case "in":
                                Console.WriteLine(number * (39.3700787 / 1.0936133) + " " + output); break;
                            case "km":
                                Console.WriteLine(number * (0.001 / 1.0936133) + " " + output); break;
                            case "ft":
                                Console.WriteLine(number * (3.2808399 / 1.0936133) + " " + output); break;
                            case "mi":
                                Console.WriteLine(number * (6.21371192E-4 / 1.0936133) + " " + output); break;
                            case "m":
                                Console.WriteLine(number * (1 / 1.0936133) + " " + output); break;
                        }
                    };
                    break;
                case "m":
                    if (output == "m")
                    {
                        Console.WriteLine(number + " " + output);
                    }
                    else
                    {
                        switch (output)
                        {
                            case "cm":
                                Console.WriteLine(number * 100 + " " + output); break;
                            case "mm":
                                Console.WriteLine(number * 1000 + " " + output); break;
                            case "in":
                                Console.WriteLine(number * 39.3700787 + " " + output); break;
                            case "km":
                                Console.WriteLine(number * 0.001 + " " + output); break;
                            case "ft":
                                Console.WriteLine(number * 3.2808399 + " " + output); break;
                            case "mi":
                                Console.WriteLine(number * 6.21371192E-4 + " " + output); break;
                            case "yd":
                                Console.WriteLine(number * 1.0936133  + " " + output); break;
                        }
                    };
                    break;
                defaut:
                   return; break;
            }
        }
    }
}