binary_number.cpp

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

bool isPossible(vector<ll>&v, ll target){
	vector<ll>temp(v.size());
	for(int i=0;i<v.size();i++){
		temp[i]=v[i];
	}
	for(ll i=temp.size()-1;i>=0;i--){
		if(temp[i]<target){
			return false;
		}
		if(i>=2){
			ll val = temp[i]-target;
			ll diff = val / 3;
			diff = min(diff, v[i]/3);
			temp[i]-=3*diff;
			temp[i-1]+=diff;
			temp[i-2]+=2*diff;
		}
	}
	return true;
}

void solve(){
	ll x;
	cin>>x;
	vector<ll>v(x);
	for(int i=0;i<x;i++){
		cin>>v[i];
	}
	ll low=1;
	ll high=1e18;
	ll ans=low;
	while(low<=high){
		ll mid = low+(high-low)/2;
		if(isPossible(v,mid)){
			low=mid+1;
			ans=max(ans,mid);
		}
		else{
			high=mid-1;
		}
	}
	cout<<ans<<endl;
}

int main(){
	ll t;
	cin>>t;
	while(t--){
		solve();
	}
	return 0;
}