using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace No47biscuit
{
    class Program
    {
        static void Main(string[] args)
        {
            //値の入力
            int N = int.Parse(Console.ReadLine());
            //計算
            double ans = System.Math.Log(N, 2);
            //表示
            Console.WriteLine(Math.Ceiling(ans));
        }
    }
}