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#include <bits/stdc++.h>

using namespace std;

unsigned long long CACHE[210000][4];
vector<long long> HOUSES;

void prepare_cache() {
    for (int i = 1; i < 210000; i++) {
        for(int j = 0; j < 4; j++) {
            if (i == j || j == 0) {
                CACHE[i][j] = 1ll;
            } else if (i < j) {
                CACHE[i][j] = 0ll;
            } else {
                CACHE[i][j] = CACHE[i - 1][j - 1] + CACHE[i - 1][j];
            }
        }
    }
}

long long binomial(int n, int k) {
    if (n < k || n < 0) {
        return 0;
    }

    if (n == k || k == 0) {
        return 1;
    }

    if (CACHE[n][k] != 0) {
        return CACHE[n][k];
    }
    return binomial(n - 1, k - 1) + binomial(n - 1, k);
}


int binary_search(int lower_bound, int upper_bound, function<bool(int)> check) {
    while (lower_bound < upper_bound) {
        long long mid = (lower_bound + upper_bound) / 2;
        if (check(mid)) {
            upper_bound = mid;
        } else {
            lower_bound = mid + 1;
        }
    }
    return lower_bound;
}


bool try_solving(int n) {
    int used_players = 0;

    if (HOUSES.size() ==1) {
        if (binomial(n , 3) >= HOUSES[0]) {
            return true;
        } else {
            return false;
        }
    }

    for (int i = 0; i < HOUSES.size(); i++) {
        if (used_players > n) {
            return false;
        }
        if (i == 0) {
            // int p = binary_search(0, n, [&](int p) {
            //     return binomial(p, 3) * binomial(p, 2) * (n - p) >= HOUSES[i];
            // });
            // if (binomial(p, 3) * binomial(p, 2) * (n - p) >= HOUSES[i]) {
            //     used_players += p;
            // } else {
            //     return false;
            // }
            int left_bound = 1;
            int right_bound = n + 1 - used_players;
            
            while (left_bound < right_bound) {
                long long mid = (left_bound + right_bound) / 2;
                if (binomial(mid, 3) + binomial(mid, 2) * (n - mid) >= HOUSES[i]) {
                    right_bound = mid;
                } else {
                    left_bound = mid + 1;
                }
            }
            if (binomial(left_bound, 3) + binomial(left_bound, 2) * (n - left_bound) >= HOUSES[i]) {
                used_players += left_bound;
            } else {
                return false;
            }
        } else if (i < HOUSES.size() - 1) {
            // int p = binary_search(1, n + 1 - used_players, [&](int p) {
            //     return binomial(p, 1) * used_players * (n - used_players - p) + binomial(p, 2) * (n - p) + binomial(p, 3) >= HOUSES[i];
            // });
            // if (binomial(p, 1) * used_players * (n - used_players - p) + binomial(p, 2) * (n - p) + binomial(p, 3) >= HOUSES[i]) {
            //     used_players += p;
            // } else {
            //     return false;
            // }
            int left_bound = 1;
            int right_bound = n + 1 - used_players;

            while (left_bound < right_bound) {
                long long mid = (left_bound + right_bound) / 2;
                if (binomial(mid, 1) * used_players * (n - used_players - mid) + binomial(mid, 2) * (n - mid) + binomial(mid, 3) >= HOUSES[i]) {
                    right_bound = mid;
                } else {
                    left_bound = mid + 1;
                }
            }
            if (binomial(left_bound, 1) * used_players * (n - used_players - left_bound) + binomial(left_bound, 2) * (n - left_bound) + binomial(left_bound, 3) >= HOUSES[i]) {
                used_players += left_bound;
            } else {
                return false;
            }
        } else {
            // int p = binary_search(2, n + 1 - used_players, [&](int p) {
            //     return binomial(p, 2) * (n - p) + binomial(p, 3) >= HOUSES[i];
            // });
            // if (binomial(p, 2) * (n - p) + binomial(p, 3) >= HOUSES[i]) {
            //     used_players += p;
            // } else {
            //     return false;
            // }
            int left_bound = 2;
            int right_bound = n + 1 - used_players;
            
            while (left_bound < right_bound) {
                long long mid = (left_bound + right_bound) / 2;
                if (binomial(mid, 2) * (n - mid) + binomial(mid, 3) >= HOUSES[i]) {
                    right_bound = mid;
                } else {
                    left_bound = mid + 1;
                }
            }
            if (binomial(left_bound, 2) * (n - left_bound) + binomial(left_bound, 3) >= HOUSES[i]) {
                used_players += left_bound;
            } else {
                return false;
            }
        }
    }
    if (used_players <= n) {
        return true;
    } else {
        return false;
    }
}



int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    prepare_cache();

    int t;
    cin >> t;
    for (int i = 0; i < t; i++) {
        int n;
        cin >> n;
        HOUSES.clear();
        for (int j = 0; j < n; j++) {
            int x;
            cin >> x;
            if (x == 0) {
                continue;
            }
            HOUSES.push_back(x);
        }
        // long long res = binary_search(3, 210000, try_solving);
        int left_bound = 3;
        int right_bound = 210000;

        while (left_bound < right_bound) {
            long long mid = (left_bound + right_bound) / 2;
            // cout << "testing: " << mid << endl;
            if (try_solving(mid)) {
                // cout << "ok" << endl;
                right_bound = mid;
            } else {
                left_bound = mid + 1;
            }
        }
        cout <<  left_bound << endl;
    }

    return 0;
}