How to call Public Void in the if-else statement?

I've been trying to run this program I made but I can't seem to get this right. How can I call my PUBLIC VOID in the if-else statement?

public class Program
{
    class ExecuteCategory
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Input category; Grades for Computing your grade average and MySavings for computing your monthly savings.");
            Console.ReadLine();
            Console.WriteLine("Input category:");
            Console.ReadLine();

/it stops here and won't run the input I called/

            bool MySavings, Grades; /above this is the main method/
            MySavings = true;
            Grades = true;

            {
                if (MySavings == true)
                {
                    Console.ReadKey(MySavings); /I need to call public void MySavings here/

                }

                else if (Grades == true)
                {
                    Console.ReadKey(Grades); /I need to call public void Grades here/

                }

                else
                {
                    Console.WriteLine("Please type a valid category:");
                    Console.ReadLine();
                }

                Console.ReadKey();
            }
        }
    class Category
    {
        public void MySavings ()
        {
            int Allowance, Savings,Food, Transpo, WFood, WTranspo, WSavings, MFood,MTranspo, MSavings;

            Console.WriteLine("Input daily allowance:");
            Allowance = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Input daily food expense:");
            Food = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Input daily transportation expense:");
            Transpo = Convert.ToInt32(Console.ReadLine());

            Savings = Allowance - (Food + Transpo);
            Console.WriteLine("Daily savings: {0}", Savings);
            Console.ReadLine();

            WFood = Food * 5;
            Console.WriteLine("Weekly Food expense: {0}",WFood);
            Console.ReadLine();
            WTranspo = Transpo * 5;
            Console.WriteLine("Weekly Food expense: {0}", WFood);
            Console.ReadLine();
            WSavings = Savings * 5;
            Console.WriteLine("Weekly Food expense: {0}", WSavings);
            Console.ReadLine();

            MFood = WFood * 4;
            Console.WriteLine("Monthly Food expense: {0}", MFood);
            Console.ReadLine();
            MTranspo = WTranspo * 4;
            Console.WriteLine("Monthly Food expense: {0}", MFood);
            Console.ReadLine();
            MSavings = WSavings * 4;
            Console.WriteLine("Monthly Food expense: {0}", MSavings);
            Console.ReadLine();



        }

        public void Grades()
        {
            int Filipino, English, Math, Science, History, Average;

            Console.WriteLine("Input grade in Filipino:");
            Filipino = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Input grade in English:");
            English = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Input grade in Math:");
            Math = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Input grade in Science:");
            Science = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("Input grade in History:");
            History = Convert.ToInt32(Console.ReadLine());

            Average = (Filipino + English + Math + Science + History) / 5;
            Console.WriteLine("Average is: {0}", Average);

        }
    }



            }


        }
    }

it won't run after I input a category. It says that "C:/Program Files/dotnet/dotnet.exe (process 14588) exited with code 0" then it closes.