#include <algorithm>
#include <iostream>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <cmath>
#include <stack>
using namespace std;

int main() {
	int N;
	cin >> N;
	int b = 1;
	int count = 0;
	while(1){
		if (b >= N) break;
		count++;
		b = b * 2;
	}
	cout << count << endl;
	return 0;
}