DZYN

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace dzyn
{
    class dzyn
    {
        static void Main(string[] args)
        {
            int n = 12;
            int dzyn = 0;

            while (n > 0)
            {
                n--;
                dzyn += n;
            }
            Console.WriteLine(dzyn);
        }
    }
}