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

namespace predavanje_4
{
    class Program
    {
        static void Main(string[] args)
        {
            // MAIN MENU
            Beginning:
            Console.WriteLine("What do you want to do? \n1. All operations \n2. Circle diameter \n3. Speed \n4. Rectangle fun. \n5. It's getting hot in here \n6. Quit\n");
            int mm = Convert.ToInt32(Console.ReadLine());

            while (mm != 6)
            {

                // ALL OPERATIONS
                if (mm == 1)
                {
                    Console.WriteLine("Enter two numbers and I'll do everything for you");
                    Console.WriteLine("First number");
                    int a = Convert.ToInt32(Console.ReadLine());
                    Console.WriteLine("Second number");
                    int b = Convert.ToInt32(Console.ReadLine());
                    Console.WriteLine("Their sum is: {0}", a + b);
                    Console.WriteLine("Their difference is {0}: ", a - b);
                    Console.WriteLine("Their multiplier is {0}: ", a * b);
                    Console.WriteLine("Their divide is: {0}\n ", a / b);
                    goto Beginning;
                }
                // DIAMETER AND AREA OF A CIRCLE
                if (mm == 2)
                {
                    Console.WriteLine("Let's do something a bit round");
                    Console.WriteLine("What is it's radius?");


                    const double pi = 3.14159265359;
                    int r = Convert.ToInt32(Console.ReadLine());
                    Console.WriteLine("It's circumference is: {0}", 2 * pi * r);
                    Console.WriteLine("It's circumference is: {0}\n", pi * r * r);
                    goto Beginning;
                }

                // SPEED AND TRAVELLED AMOUNT
                if (mm == 3)
                {
                    Console.WriteLine("Let's see how fast you are");
                    Console.WriteLine("How fast are you in km/h?");
                    int v = Convert.ToInt32(Console.ReadLine());
                    Console.WriteLine("How many hours have passed?");
                    int t = Convert.ToInt32(Console.ReadLine());
                    Console.WriteLine("You have travelled {0} kilometers\n", v * t);
                    goto Beginning;
                }

                // RECTANGLE
                if (mm == 4)
                {
                   Console.WriteLine("Rectangle fun!");
                    Console.WriteLine("Side a?");
                    int sidea = Convert.ToInt32(Console.ReadLine());
                    Console.WriteLine("Side b?");
                    int sideb = Convert.ToInt32(Console.ReadLine());
                    Console.WriteLine("It's diagonal is {0}.\nIt's area is {1}. \nIt's cirfumference is {2}\n", Math.Sqrt(sidea * sidea+sideb*sideb), sidea*sideb, 2*sidea + 2*sideb);
                    goto Beginning;
                }

                // CELSIUS AND FAHRENHEIT
                if (mm == 5)
                {
                    Console.WriteLine("Do want:\n1. C to F\n2. F to C");
                    int cfchoice = Convert.ToInt32(Console.ReadLine());
                    Console.WriteLine("Enter the temperature");
                    int temp = Convert.ToInt32(Console.ReadLine());

                    if (cfchoice == 1)
                    {
                        Console.WriteLine("{0} C is {1} F\n", temp, temp * 9 / 5 + 32);

                    }
                    if (cfchoice == 2)
                    {
                        Console.WriteLine("{0} K is {1} C\n", temp, (temp-32)*5/9);

                    }
                    goto Beginning;

                }

            }
        }
    }
}