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

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            var N = long.Parse(Console.ReadLine());
            long answer = 0;
            for (long i = 1; i * i <= N; i++) 
            {
                if(N % i == 0)
                {
                    answer += i;
                    if(i * i != N)
                    {
                        answer += N / i;
                    }
                }
            }
            Console.WriteLine(answer);
        }
    }
}