using System;

public class Program

{

    public static void Main()

    {

        var count = 0; 

        for(var i = 1; i <= 100; i++)

        {

            if(i%3 == 0)

                count++; 

        }

        Console.WriteLine("There are {0} numbers divideble by 3 between 1 and 100.", count);

    var summary = 0; 

        while(true)

        {

            Console.WriteLine("Enter number or to exit enter ok:");

            var input = Console.ReadLine();

            if(input == "ok")

                break;

            summary+= Convert.ToInt32(input);

        }

        Console.WriteLine("Summary of all numbers you have entered is {0}.", summary);

    }

}