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


int a[200000];

ll calc(ll l, ll r, ll x) {
    return (x*(x-1)*(x-2))/6+(((x*(x-1))/2) * (l+r))+(l*r*x);
}

bool ok(int n, int k) {
    int l = 0, r = k;
    for (int i = 0; i < n; i++) {
        int p = 0, q = r+1, mid;
        while (p < q) {
            mid = (p+q)/2;
            if (calc(l, r-mid, mid) >= a[i]) q = mid;
            else p = mid+1;
        }
        if (p == r+1) return false;
        l += p;
        r -= p;
    }
    return true;
}


void solve() {
    int n; cin >> n;
    
    int cnt = 0;
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    int p = 0, q = 250000, mid;
    while (p < q) {
        mid = (p+q)/2;
        if (ok(n, mid)) q = mid;
        else p = mid+1;
    }
    cout << p << '\n';
}

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