using System;
using System.Linq;

class Program
{
    static void Main(string[] args)
    {
        // No.47 ポケットを叩くとビスケットが２倍

        int n = int.Parse(Console.ReadLine());
        int biscuits = 1, count = 0;

        while (biscuits < n)
        {
            biscuits += biscuits;
            count++;
        }
        Console.WriteLine(count);
    }
}