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

namespace lecture
{
    class Program
    {

        static void Main(string[] args)
        {
            // 入力
            int N = int.Parse(Console.ReadLine());
            int a = 1;
            int count = 0;

            while (true)
            {
                if (a >= N)
                {
                    Console.WriteLine(count);
                    break;
                }
                a *= 2;
                count++;
            }
        }
    }
}