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

namespace yukicoder_47 {
    class Program {
        static void Main(string[] args) {
            int n = int.Parse(Console.ReadLine());
            int count = 0;
            for(int i = 0; n - Math.Pow(2, i) > 0; i++) {
                count++;
            }
            Console.WriteLine(count);
            Console.ReadLine();
        }
    }
}