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)
        {
            int N = int.Parse(Console.ReadLine());
            int i = 1;
            int answer = 0;
            while(true)
            {
                if(N % i == 0)
                {
                    answer += N / i;
                }
                i++;
                if(i > N)
                {
                    break;
                }
            }
            Console.WriteLine(answer);
        }
    }
}