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

const ll MAXN = 2e5 + 5;

ll tab[MAXN];

ll wynik(ll val, ll pref, ll suff){
    if(val == 0) return 0;
    if(val == 1) return val * pref * suff;
    if(val == 2) return val * pref * suff + val * (val - 1) / 2 * (pref + suff);
    else return val * pref * suff + val * (val - 1) / 2 * (pref + suff) + val * (val - 1) * (val - 2) / 6;
}

ll zdobadz(ll pref, ll sum, ll i){
    ll p = 0;
    ll k = sum - pref;
    while(p != k){
        ll sr = (p + k) / 2;
        ll suff = sum - pref - sr;
        ll v = wynik(sr, pref, suff);
        if(v >= tab[i]){
            k = sr;
        } 
        else{
            p = sr + 1;
        }
    }
    return p;
}

bool czy(ll val, ll n){
    ll pref = 0;
    for(int i = 1; i <= n; ++i){
        ll il = zdobadz(pref, val, i);
        if(pref + il > val) return false;
        if(wynik(il, pref, val - pref - il) < tab[i]) return false;
        pref += il;
    }
    return true;
}


void solve(){
    ll n;
    cin >> n;
    for(int i = 1; i <= n; ++i){
        cin >> tab[i];
    }
    ll p = 3;
    ll k = 3e6;
    while(p != k){
        ll sr = (p + k) / 2;
        if(czy(sr, n)){
            k = sr;
        }
        else{
            p = sr + 1;
        }
    }
    cout << p << "\n";
    for(int i = 1; i <= n; ++i){
        tab[i] = 0;
    }
    return;
}

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