#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
#include <stack>
#include <cmath>
#define REP(i,n) for (int i=0;i<(n);i++)

using namespace std;

int main(){
	int N;
	cin >> N;

	cout << ceil(log2(N)) << endl;
	return 0;
}