using System;

public class Hello
{
    public static void Main()
    {
        var n = int.Parse(Console.ReadLine().Trim());
        var ans = getA(n);
        Console.WriteLine(ans);
    }
    public static int getA(int n)
    {
        var ans = 0;
        while (n > 1)
        {
            if (n % 2 == 0) { n /= 2;  ans++;            }
            else { n = (n + 1) / 2;  ans += 2; }
        }
        return ans;
    }
}