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#include <bits/stdc++.h>

using namespace std;
typedef unsigned long long ll;
#define rep(i, n) for (int i = 0; i < (n); i++)
#define pb push_back
#define st first
#define nd second
const int MAXN = 2e5 + 7;
ll T[MAXN];

ll policz(ll l, ll x, ll r) {
    ll A = l * x * r;
    ll B = (l + r) * ((x * (x - 1))/2);
    ll C = (x * (x - 1) * (x - 2))/6;
    ll W = A + B + C;
    return W;
}

ll znajdz(ll ile, ll potrzeba, ll r) {
    ll poc = 0;
    ll kon = ile;
    // cout << "potrzeba = " << potrzeba << " policz = " << policz(0, ile, r) << '\n';
    if (policz(0, ile, r) < potrzeba) {
        return ile + 1;
    }
    ll odp = ile;
    while (poc < kon) {
        ll sr = (poc + kon)/2;
        if (policz(ile - sr, sr, r) >= potrzeba) {
            odp = sr;
            kon = sr;
        }
        else {
            poc = sr + 1;
        }
    }
    return odp;
}

bool spr(int n, ll ile) {
    ll r = 0;
    // cout << "ile = " << ile << '\n';
    for (int i = n - 1; i >= 0; i--) {
        ll x = znajdz(ile, T[i], r);
        // cout << "x = " << x << '\n';
        if (x > ile) {
            return false;
        }
        ile -= x;
        r += x;
    }
    return true;
}

void solve() {
    int n;
    cin >> n;
    rep(i, n) {
        cin >> T[i];
    }
    ll poc = 0;
    ll kon = 3e6;
    ll odp = 0;
    while (poc < kon) {
        ll sr = (poc + kon)/2;
        if (spr(n, sr)) {
            odp = sr;
            kon = sr;
        }
        else {
            poc = sr + 1;
        }
    }
    cout << odp << '\n';
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int t;
    cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}