using System;

​

public class Program

{

    public static void Main()

    {

        string vstup = "";

        double cislo = 0;

        bool jeCislo = false;

        string cin = "";

        double druheCislo = 0;

        double vysledek = 0;

        while (!jeCislo)

        {

            Console.WriteLine("Zadej Cislo:");

            vstup = Console.ReadLine();

            jeCislo = double.TryParse(vstup, out cislo);

        }

​

        while (!(cin == "+" || cin == "-" || cin == "*" || cin == "/"))

        {

            Console.WriteLine("Jak chces jednat? Muzes vybrat +, -, *, /");

            cin = Console.ReadLine();

        }

​

        jeCislo = false;

        while (!jeCislo)

        {

            Console.WriteLine("Zadej Cislo:");

            vstup = Console.ReadLine();

            jeCislo = double.TryParse(vstup, out druheCislo);

        }

​

        switch (cin)

        {

            case "+":

                vysledek = cislo + druheCislo;

                break;

            case "-":

                vysledek = cislo - druheCislo;

                break;

            case "*":

                vysledek = cislo * druheCislo;

                break;

            case "/":

                vysledek = cislo / druheCislo;

                break;

        }

        Console.WriteLine ("{0} {1} {2} = {3}", cislo, cin, druheCislo, vysledek);

​

    }

}