using System;

namespace Methods
{
    class Program
    {
        static void Main(string[] args)

            string command = Console.ReadLine();
            double a = double.Parse(Console.ReadLine());
            double b = double.Parse(Console.ReadLine());
            switch (command)
            { case "add":
                    Add(a, b);
                    break;
                case "multipy":
                    multiply(a, b);
                    break;
                case "divide":
                    divide(a, b);
                    break;
                case "subtract":
                    sub(a, b);
                    break;
            }
        }

       static void sub(double a, double b)
        {
            Console.WriteLine(a-b);
        }

        static void divide(double a, double b)
        {
            Console.WriteLine(a/b);

        }

        static void multiply(double a, double b)
        {
            Console.WriteLine(a*b);
        }

        static void Add(double a, double b)
        {
            Console.WriteLine(a+b);
        }
    }
}