#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#include <tuple>
#include <queue>
#include <deque>
#include <map>
#include <set>
#include <cmath>
#include <iomanip>
#define rep(i, n) for(int i = 0; i < (int)(n); ++i)
using namespace std;

int main(void) {
    int N;
    cin >> N;
    
    int ans = 0;
    int x = 1;
    while (x < N) {
        ++ans;
        x *= 2;
    }
    cout << ans << endl;
}