using System;

namespace Probrem043
{
    class Program
    {
        static void Main(string[] args)
        {
            var input = Console.ReadLine().Split(' ');
            var eat = int.Parse(input[0]); //10
            int bis = 1;
            int ans = 0;

            while(true){
                if (eat <= bis) break;
                bis = bis * 2;
                ans += 1;
            }
                //var b = decimal.Parse(input[1]);
                //var ans = Math.Ceiling(b / a);
                
                Console.WriteLine(ans);
        }
    }
}