#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n) - 1; i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r) - 1;i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
template <class T, class F>
T binarySearch(T ok, T ng, const F &f) {
	while (abs(ok - ng) > 1) {
		T mid = (ok + ng) / 2;
		(f(mid) ? ok : ng) = mid;
	}
	return ok;
}
int main() {
	std::ios::sync_with_stdio(false);
	std::cin.tie(nullptr);
	int n; cin >> n;
	vector<long long>pw2(61, 1);
	rep2(i, 1, 61)pw2[i] = pw2[i - 1] * 2;
	vector<long long>h(n);
	rep(i, n)cin >> h[i];
	auto f = [&](const long long x)->bool {
		priority_queue<long long>pq;
		rep(i, n)pq.push(h[i]);
		auto cx = x;
		while (cx) {
			if (pq.empty())break;
			auto d = pw2[min(cx - 1, (long long)pw2.size() - 1)];
			auto top = pq.top();
			pq.pop();
			top -= d;
			if (top > 0) {
				pq.push(top);
			}
			cx--;
		}
		return pq.empty();
	};
	auto ans = binarySearch<int>(200, 0, f);
	cout << ans << endl;
	return 0;
}