using System;

namespace yukicoder_no47
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            
            int N = int.Parse(Console.ReadLine());

			int i = 0;
			while (true)
			{
				if (N <= (int)Math.Pow(2, i)) break;
				i++;
			}

			Console.WriteLine("{0}", i);
        }
    }
}