using System;
using System.Linq;

public class yukicoder{
    public static void Main(){
        int n = int.Parse(Console.ReadLine());
        int b = 1;
        int tap = 0;
        
        while(true)
        {
            if(n - b <= 0)
            {
                break;
            }
            b = b * 2;
            tap ++;
        }
        
        Console.WriteLine(tap);

    }
}