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#include <bits/stdc++.h>
using namespace std;

#define mp make_pair
#define pb push_back
#define st first
#define nd second
#define fi first
#define se second
#define vt vector
#define FOR(a, b, c)  for(int a=b; a<c; ++a)
#define all(a)     (a).begin(),(a).end()
#define sz(a)      (int)(a).size()

typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
typedef vector<int> vi; 
typedef vector<ll> vll;
typedef pii PII;
typedef pll PLL;

constexpr ll nax = 2e5+6969, INF = 1e9+2137;
constexpr ld eps = 1e-9;

mt19937_64 rng(6969);
// mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());

inline ll rand(ll l, ll r) {
	return uniform_int_distribution<ll>(l, r)(rng);
}

int n; 

bool satisfy(ll x, ll a, ll m, ll L) {
    ll x3 = x * (x - 1) * (x - 2) / 6; 
    ll x2 = x * (x - 1) / 2; 
    if(x3 >= a)
        return true; 
    if(x3 + x2 * (m - x) >= a)
        return true; 
    if(x3 + x2 * (m - x) + L * (m - L - x) * x >= a)
        return true; 
    return false; 
}

bool check(ll m, const vll & v) {
    ll L = 0; 

    for(auto e: v) {
        if(e == 0)
            continue; 

        ll lf = 1, rg = m - L; 
        ll ans = -1;
        
        while(lf <= rg) {
            ll mid = (lf + rg) / 2; 
            if(satisfy(mid, e, m, L)) {
                ans = mid; 
                rg = mid - 1; 
            }
            else {
                lf = lf + 1; 
            }
        }

        if(ans == -1)
            return false; 

        L += ans; 
        if(L > m)
            return false; 
    }
    return L <= m; 
}

void test_case() {
    cin >> n; 
    vll v(n); 
    ll sum = 0; 
    for(auto &e: v) {
        cin >> e; 
        sum += e; 
    }

    ll lf = 3, rg = sum * 3; 
    ll ans = sum * 3; 

    while(lf <= rg) {
        ll mid = (lf + rg) / 2; 
        if(check(mid, v)) {
            rg = mid - 1; 
            ans = mid; 
        }
        else {
            lf = mid + 1; 
        }
    }

    cout << ans << "\n"; 

}

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

    int qq; 
    cin >> qq; 
    while(qq--) {
        test_case(); 
    }

    return 0;
}