using System;
using System.Collections.Generic;

namespace Application
{
	class MainClass
	{
		public static void Main (string[] args)
		{
            var N = scanNextDigit();

            writeLine(Math.Ceiling(Math.Log((double)N, 2)));
		}

        static void writeLine(object o)
        {
            System.Console.WriteLine(o.ToString());
        }

        static int[] scanNextDigits(int count)
        {
            var res = new List<int>();

            for (int i = 0; i < count; i++)
            {
                res.Add(scanNextDigit());
            }

            return res.ToArray();
        }

        static string scanNextToken()
        {
            int i;
            var r = new List<char>();

            while ((i = System.Console.Read()) >= 0)
            {
                var c = Convert.ToChar(i);
                if (!isSpace(c))
                {
                    r.Add(c);
                }
                else if (r.Count > 0)
                {
                    break;
                }
            }

            return new string(r.ToArray());
        }

        static bool isSpace(char c)
        {
            switch (c)
            {
                case '\t':
                case '\n':
                case ' ':
                    return true;
                default:
                    return false;
            }
        }

        static int scanNextDigit()
        {
            var token = scanNextToken();

            return int.Parse(token);
        }

	}
}