using System;
using System.Linq;

namespace TestConsole
{
    class Program
    {
        static void Main(string[] args)
        {
            var input = int.Parse(Console.ReadLine());
            int count = -1;

            if (input > 1)
            {
                count++;
                if (input % 2 == 1)
                {
                    count++;
                    input--;
                }

                count += (int)Math.Ceiling(Math.Log(input / 2, 2));
            }
            Console.WriteLine(count + 1);
        }
    }
}