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#include "bits/stdc++.h"
using namespace std;
#define all(x) x.begin(),x.end()
template<typename A, typename B> ostream& operator<<(ostream &os, const pair<A, B> &p) { return os << p.first << " " << p.second; }
template<typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type> ostream& operator<<(ostream &os, const T_container &v) { string sep; for (const T &x : v) os << sep << x, sep = " "; return os; }
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#define ASSERT(...) 42
#endif
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> pi;
const ll oo = 1e18;
ll f(ll a,ll b, ll mid) {
    ll cur=0;
    cur+=mid*(mid-1)*(mid-2)/6;
    cur+=mid*(mid-1)/2 * (a + b-mid); // all others with 2 of mine...
    cur+=a * mid * (b-mid);
    return cur;
}
ll finv(ll a, ll b, ll want) {
    ll lo = 0, hi = min(b,200LL);
    while(lo<hi) {
        ll mid = (lo+hi)/2;
        // all cases

        if(f(a,b,mid) >=want) {
            hi = mid;
        } else lo = mid+1;
    }
    if(f(a,b,lo)<want) return oo;
    return lo;


}
void solve() {
    int n; cin >> n;
    vi a(n);
    for(auto& i : a) cin >> i;
    ll lo =0, hi = 1e3*n;
    while(lo<hi) {
        ll mid = (lo+hi)/2;
        ll left = mid;
        ll behind = 0;
        bool bad=0;
        for(int i=0;i<n;++i) {
            auto res=  finv(behind,left,a[i]);
            if(res>left) {
                bad=1;
                break;
            } else {
                behind+=res;
                left-=res;
            }
        }
        if(!bad) hi = mid;
        else lo = mid+1;
    }
    cout << lo << '\n';

}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int t; cin >> t;
    while(t--) solve();
}