using System;

namespace yukicoder
{
    class Program
    {

        static void Main(string[] args)
        {
            int N = int.Parse(Console.ReadLine());
            int i = 1;
            int count = 0;
                      
            while(i < N)
            {
                i *= 2;
                count++;
            }
            Console.WriteLine(count);
        }
    }
}