using System;
class Program
{
    static void Main(string[] args)
    {
        string s = Console.ReadLine();
        if(long.Parse(s)==1){
                Console.WriteLine("0");
                return;            
        }
        for(long Loop1 = 1; Loop1 <= (long)Math.Pow(10, 8); Loop1++)
        {
            if (long.Parse(s)<=Max_Get_biscuit(Loop1))
            {
                Console.WriteLine(Loop1.ToString());
                return;
            }
        }
    }
    static long Max_Get_biscuit(long Count) {
        return (long)Math.Pow(2, (Count));
    }
}