using System;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Temperature Converter");

        Console.WriteLine("        ");

        double first;

        string second;

        double answer;

        string unit;

        Console.WriteLine("Enter the starting temperature (number)");

        first = Double.Parse(Console.ReadLine());

        Console.WriteLine("        ");

        Console.WriteLine("Choose its temperature unit (a=Fahrenheit, b=Celsius, or c=Kelvin)");

        unit = Convert.ToString(Console.ReadLine());

        Console.WriteLine("        ");

        Console.WriteLine("Choose the unit you want to convert it to (a=Fahrenheit, b=Celsius, or c=Kelvin)");

        second = Convert.ToString(Console.ReadLine());

        //Note: The next two are for converting Fahrenheit to the two.

        if (unit=="a" && second=="b")

        {

            answer=(first-32)*5/9;

            Console.WriteLine("        ");

            Console.WriteLine("Your current temperature is now in Celsius:");

            Console.WriteLine(answer);

        } 

        if (unit=="a" && second=="c")

        {

            answer=(first-32)*5/9+273.15;

            Console.WriteLine("        ");

            Console.WriteLine("Your current temperature is now in Kelvin:");

            Console.WriteLine(answer);

        } 

        //Note: The next two are for converting Celsius to the two.

        if (unit=="b" && second=="a")

        {

            answer=(first*9)/5+32;

            Console.WriteLine("        ");

            Console.WriteLine("Your current temperature is now in Fahrenheit:");

            Console.WriteLine(answer);

        } 

        if (unit=="b" && second=="c")

        {

            answer=first+273.15; 

            Console.WriteLine("        ");

            Console.WriteLine("Your current temperature is now in Kelvin:");

            Console.WriteLine(answer);

        }

        //Note: The next two are for converting Kelvin to the two.

        if (unit=="c" && second=="a")

        {

            answer=(first-273.15)*9/5+32;

            Console.WriteLine("        ");

            Console.WriteLine("Your current temperature is now in Kelvin:");

            Console.WriteLine(answer);

        }

        if (unit=="c" && second=="b")

        {

            answer=first-273.15; 

            Console.WriteLine("        ");

            Console.WriteLine("Your current temperature is now in Celsius: ");

            Console.WriteLine(answer);

        } 

        //Note: The following three if statements are for if you put the same units.

        if (unit=="a" && second=="a")

        {

            Console.WriteLine("        ");

            Console.WriteLine("You cannot convert that ");

        } 

        if (unit=="b" && second=="b")

        {

            Console.WriteLine("        ");

            Console.WriteLine("You cannot convert that ");

        } 

        if (unit=="c" && second=="c")

        {

            Console.WriteLine("        ");

            Console.WriteLine("You cannot convert that ");

        } 

}}