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#include <bits/stdc++.h>

// #pragma GCC optimize("Ofast")
// #pragma GCC target("avx,avx2")

#define int long long

using namespace std;

// int min_ludzie(int lewo, int prawo, int wymagane)
// {
// 	if (wymagane == 0)
// 		return 0;

// 	for (int biore = 1; biore < 190; biore++)
// 	{
// 		for (int dokladam = 0; dokladam <= biore; dokladam++)
// 		{
// 			int b = biore - dokladam;
// 			int b3 = (b * (b - 1) * (b - 2)) / 6;
// 			int b2 = (b * (b - 1)) / 2;
// 			int c = prawo - b;
// 			int a = lewo + dokladam;

// 			if (b3 + a * c * b + (a + c) * b2 >= wymagane)
// 			{
// 				return biore;
// 			}
// 		}
// 	}
// 	return 999999999;
// }

int min_ludzie(int lewo, int prawo, int wymagane)
{
	if (wymagane == 0)
		return 0;

	for (int b = 1; b < 190; b++)
	{
		int b3 = (b * (b - 1) * (b - 2)) / 6;
		int b2 = (b * (b - 1)) / 2;
		int c = prawo - b;

		if (b3 + lewo * c * b + (lewo + c) * b2 >= wymagane)
		{
			return b;
		}
	}
	return 999999999;
}

bool min_ludzie_last(int lewo, int b, int wymagane)
{
	int b3 = (b * (b - 1) * (b - 2)) / 6;
	int b2 = (b * (b - 1)) / 2;

	if (b3 + lewo * b2 >= wymagane)
	{
		return true;
	}
	return false;
}

int odp(int n, vector<int> &v)
{
	int guess_min = 0;
	int guess_max = 190 * n;
	while (guess_min < guess_max)
	{
		int guess = (guess_min + guess_max) / 2;

		int lewo = 0;
		for (int i = 0; i < n - 1; i++)
		{
			// wez minimum dla v[i]
			if (lewo > guess)
			{
				break;
			}
			int wez = min_ludzie(lewo, guess - lewo, v[i]);
			// cerr << i << "BIORE " << wez << "bo guess = " << guess << "lewo=" << lewo << "prawo=" << guess - lewo << endl;
			lewo += wez;
		}
		if (lewo <= guess && min_ludzie_last(lewo, guess - lewo, v[n - 1]))
		{
			guess_max = guess;
		}
		else
		{
			guess_min = guess + 1;
		}
	}
	return guess_min;
}

int32_t main()
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);

	int T;
	cin >> T;
	while (T--)
	{
		int n;
		cin >> n;
		vector<int> v(n);
		for (int i = 0; i < n; i++)
		{
			int a;
			cin >> a;
			v[i] = a;
		}

		int odp1 = odp(n, v);

		reverse(v.begin(), v.end());

		int odp2 = odp(n, v);

		cout << min(odp1, odp2) << endl;
	}
}