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#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
const int MAXN=2e5;
const int MAXANS=2e5+100;

int n;
ll arr[MAXN+5];

ll po2(ll x)
{
	return x*(x-1)/2;
}

ll po3(ll x)
{
	return x*(x-1)*(x-2)/6;
}

ll combin(ll a, ll L, ll All)
{
	return po3(a)+po2(a)*(All-a) + a*L*(All-L-a);
}

bool check(ll All)
{
	ll L=0;
	while(combin(L,0,All) < arr[0]){
		L++;
		if(L > All) return 0;
	}
	for(int i=1;i<n;i++){
		if(arr[i]==0) continue;
		ll a=1;
		ll prev = combin(a,L,All);
		while(combin(a, L, All) < arr[i]){
			if(combin(a+1, L, All) > combin(a, L+1, All)){
				a++;
			}
			else{
				L++;
			}
			if(combin(a,L,All) < prev) return 0;
			prev=combin(a,L,All);
			if(a+L > All) return 0;
		}
		L+=a;
	}
	return 1;
}

int bs1(int l, int r)
{
	if(l==r) return l;
	int mid=(l+r)/2;
	if(check(mid)) return bs1(l, mid);
	else return bs1(mid+1,r);
}

void solve()
{
	cin >> n;
	for(int i=0;i<n;i++){
		cin >> arr[i];
	}
	cout << bs1(1, MAXANS) << "\n";
}

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