Calculation

using System;
using System.Collections.Generic;

class Program
{
    public static void Main(string[] args)
    {
        string calculation = Console.ReadLine().ToLower();
        int a = int.Parse(Console.ReadLine());
        int b = int.Parse(Console.ReadLine());
        switch (calculation)
        {
            case "add":
                Add(a, b);
                break;
            case "subtract":
                Subtract(a, b);
                break;
            case "multiply":
                Multyply(a, b);
                break;
            case "divide":
                Divide(a, b);
                break;
        }
    }
    public static void Add(int a,int b)
    {
        Console.WriteLine(a+b);
    }
    public static void Subtract(int a, int b)
    {
        Console.WriteLine(a-b);
    }
    public static void Multyply(int a, int b)
    {
        Console.WriteLine(a*b);
    }
    public static void Divide(int a, int b)
    {
        Console.WriteLine(a/b);
    }
}