#include <algorithm>
#include <numeric>
#include <string>
#include <vector>
#include <iostream>
#include <queue>
#include <utility>
#include <cmath>
#include <bitset>
using namespace std;

using ull = unsigned long long;


int main()
{
    ull n;
    cin >> n;

    int num = 1;
    int count = 0;

    while(num < n)
    {
        num *=2;
        ++count;
    }

    cout << count << endl;
}