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#include <bits/stdc++.h>
#define fi first
#define sc second
#define pb push_back
#define rep(i,p,k) for(int i=(p);i<(k);++i)
#define forn(i,p,k) for(int i=(p);i<=(k);++i)
#define forr(i,k,p) for(int i=(k)-1;i>=(p);--i)
#define each(a,b) for(auto&a:b)
#define all(v)  begin(v), end(v)
#define RET(smth)   return void(cout<<(smth)<<'\n');
#define sz(v) (int)v.size()
using namespace std;
using pii = pair<int,int>;
using ll = long long;
using lll = __int128_t;
using Vi = vector<int>;
#ifdef DEBUG
#include "debug.h"
#else
#define debug(...) ;
#endif


int find_for(int x, int a, int n) {
    for(ll b = 0, c = n - a; c >= 0; b++, c--) {
        ll t = (b*(b-1)*(b-2))/6 + (a+c)*b*(b-1)/2 + a*b*c;
        if(t >= x) return b;
    }
    return -1;
}

struct MAIN {
    void TEST() {
        int n; cin >> n;
        vector<int> t(n);
        for(auto&v:t) cin >> v;
        auto check = [&](int x) {
            int a = 0;
            for(auto v : t) {
                int r = find_for(v, a, x);
                if(r == -1) return false;
                a += r;
            }
            return true;
        };
        int p = 0, k = 200'000'000;
        while(p < k) {
            int m = (p+k)/2;
            if(check(m)) k = m;
            else         p = m+1;
        }
        cout << p << '\n';
    }
};

int main() {
#ifndef DEBUG
    cin.tie(0) -> sync_with_stdio(0);
#endif
    int Z = 1;
    cin>>Z;
    while(Z--)  MAIN{}.TEST();
    return 0;
}