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

const int maxn = 2e5 + 7;
vector<int> arr(maxn);


int check_point(int l, int x, int k){
    int r = k - x - l;
    int sum1 = l*x*r;
    int sum2 = 0, sum3 = 0;
    if(x >= 2) sum2 = (x*(x-1)/2)*(k - x);
    if(x >= 3) sum3 = (x*(x-1)*(x-2))/6;
    return sum1 + sum2 + sum3;
}
bool check(int n, int k){
    int l = 0;
    for(int i = 0; i < n - 1; i++){
        int lo = 0, hi = k - l;
        int res = -1;
        while(lo <= hi){
            int mid = (lo + hi)/2;
            if(check_point(l, mid, k) >= arr[i]){
                res = mid;
                hi = mid - 1;
            }
            else lo = mid + 1;
        }
        //cout << i << " " << res << endl;
        if(res == -1) return false;
        l += res;
    }
    return(check_point(l, k - l, k) >= arr[n - 1]);
}

void solve(){
    int n; cin >> n;
    for(int i = 0; i < n; i++) cin >> arr[i];
    int l = 3, r = 1e6 + 7, mid;
    int res = r;
    //cout << check(n, 3) << "\n";
    while(l <= r){
        mid = (l + r)/2;
        if(check(n, mid)){
            res = min(res, mid);
            r = mid - 1;
        }
        else l = mid + 1;
    }
    cout << res << "\n";
}

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