using System;

namespace No._47
{
    class Program
    {
        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());
            int count = 0;
            int stock = 1;

            while (stock < N)
            {
                stock *= 2;
                count++;
            }

            Console.WriteLine(count);
        }
    }
}