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// PA2025, @mjm, r5c-tur

#include <cstdio>
#include <string>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <unordered_map>
#include <algorithm>
#include <functional>
using namespace std;
using ull = unsigned long long;
inline int nextInt() { int n; scanf("%d", &n); return n; }
inline ull nextUll() { ull n; scanf("%llu", &n); return n; }
inline int myMin(int a, int b) { return a <= b ? a : b; }
inline ull myMax(ull a, ull b) { return a >= b ? a : b; }

const int N = 200000 + 9;
int n;
ull a[N];

bool myTest(int cnt) {
	int done = 0;
	int todo = cnt;
	for (int i = 0; i < n; ++i) {
		const ull ZERO = 0;
		const ull ONE = 1;
		if (ZERO == a[i]) continue;
		int found = -1;
		int maxX = myMin(todo, 200);
		for (int x=1; x<=maxX; ++x) {
			ull cur = 0;
			// ABC
			cur += ONE * done * x * (todo - x);
			// ABB + BBC
			cur += ONE * x * (x - 1) * (cnt - x) / 2;
			// BBB
			cur += ONE * x * (x - 1) * (x - 2) / 6;

			if (cur >= a[i]) {
				found = x;
				break;
			}
		}
		if (found < 0) return false;
		done += found;
		todo -= found;
	}
	return true;
}

int solve() {
	int a = 2;
	int b = n * 200;

	while (a + 1 < b) {
		int c = (a + b) / 2;
		bool ok = myTest(c);
		if (ok)
			b = c;
		else
			a = c;
	}

	return b;
}

int main() {
	int TC = nextInt();
	for (int tc = 0; tc < TC; ++tc) {
		n = nextInt();
		for (int i = 0; i < n; ++i)
			a[i] = nextInt();
		int res = solve();
		printf("%d\n", res);
	}

	return 0;
}