using System;
using System.Linq;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            var nums = new []{ 7, 2, 5, 5, 7, 6, 7 };
            var ans = 0;

            nums.GroupBy(x => x).Select(x =>
            {
                ans += x.Key;
                return x.Key;
            });

            Console.WriteLine(ans);
        }
    }
}