using System;

public class Paiza
{
    public static void Main()
    {
        var n = int.Parse(Console.ReadLine().Trim());
        if (n == 1) { Console.WriteLine(0); goto end; }
        var a = 1;
        for (int i = 1; i <= 27; i++)
        {
            a *= 2;
            if (a >= n) { Console.WriteLine(i); break; }
        }
        end:;
    }
}