#include <vector>
#include <iostream>
#include <string>
#include <sstream>
#include <algorithm>
#include <utility>
#include <map>
#include <cmath>

using namespace std;
typedef long long ll;
typedef pair<ll,ll> P;

int main(){
	ll n;
	cin >> n;
	ll t = 1;
	int ans = 0;
	while(t < n)t *= 2,ans++;
	cout << ans << endl;
}