using System;

public class Program

{

    static void Menu()

    {

        Console.WriteLine("Welcome to my simple calculator: Do you want to:");

        Console.WriteLine("1 : Add two numbers");

        Console.WriteLine("2 : Subtract two numbers");

        Console.WriteLine("3 : Multiply two numbers");

        Console.WriteLine("4 : Divide two numbers");

    }

    public static void Main()

    {

        int NumOne;

        int NumTwo;

        int NumThree;

        int choice;

        Menu();

        choice = int.Parse(Console.ReadLine());

        Console.WriteLine("Please pick your first number");

        NumOne = int.Parse(Console.ReadLine());

        Console.WriteLine("Please pick your second number");

        NumTwo = int.Parse(Console.ReadLine());

        if (choice == 1)

        {

            Add(NumOne, NumTwo);

        }

        else if (choice == 2)

        {

            Sub(NumOne, NumTwo);

        }

        else if (choice == 3)

        {

            Mul(NumOne, NumTwo);

        }

        else if (choice == 4)

        {

            Div(NumOne,NumTwo);

        }

    }

    static void Add(int NumOne, int NumTwo)

    {

        int NumThree = NumOne + NumTwo;

        Console.WriteLine("{0} + {1} = {2}",NumOne, NumTwo, NumThree);

    }

    static void Sub(int NumOne, int NumTwo)

    {

        int NumThree = NumOne - NumTwo;

        Console.WriteLine("{0} - {1} = {2}",NumOne, NumTwo, NumThree);

    }

    static void Mul(int NumOne, int NumTwo)

    {

        int NumThree = NumOne * NumTwo;

        Console.WriteLine("{0} x {1} = {2}",NumOne, NumTwo, NumThree);

    }

    static void Div(int NumOne, int NumTwo)

    {

        int NumThree = NumOne / NumTwo;

        Console.WriteLine("{0} / {1} = {2}",NumOne, NumTwo, NumThree);

    }

}