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

namespace yukicorder
{
	class Program
	{
		static void Main(string[] args)
		{
			var n = int.Parse(Console.ReadLine());

			int i =  1;
			double cnt = 0;
			while(n > cnt)
			{
				i++;
				cnt = Math.Pow(2 , i);
			}

			Console.WriteLine(n == 1 ? 0 : i);
		}
	}
}