#include <algorithm>
#include <iostream>
#include <iomanip>
#include <cstring>
#include <string>
#include <vector>
#include <queue>
#include <cmath>
#include <stack>
#include <set>
#include <map>
typedef long long ll;
typedef unsigned int uint;
using namespace std;

int n;
int ans = 0;



int main() {
	cin >> n;

	int f_bis = 1;
	while (n > f_bis) {
		f_bis *= 2;
		ans++;
	}
	cout << ans << endl;
}