#include <algorithm>
#include <iostream>
#include <queue>
#include <vector>

using LL = long long;

int main() {
    int N;
    std::cin >> N;
    std::vector<LL> H(N);
    for (auto& x : H) {
        std::cin >> x;
    }
    std::sort(H.begin(), H.end());
    auto check = [&](int x) -> bool {
        std::priority_queue<LL> q;
        for (int i = 0; i < N - std::max(x - 60, 0); i++) {
            q.emplace(H[i]);
        }
        for (x = std::min(x, 60) - 1; x >= 0; x--) {
            if (q.empty()) {
                break;
            }
            auto t = q.top();
            q.pop();
            t -= (1LL << x);
            if (t > 0) {
                q.emplace(t);
            }
        }
        return q.empty();
    };
    int left = N;
    int right = N + 60;
    while (left < right) {
        int mid = (left + right) / 2;
        if (check(mid)) {
            right = mid;
        } else {
            left = mid + 1;
        }
    }
    std::cout << left << std::endl;
    return 0;
}