#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define _GLIBCXX_DEBUG
using namespace std;
using std::cout;
using std::cin;
using std::endl;
using ll=long long;
using ld=long double;
ll ILL=1167167167167167167;
const int INF=2100000000;
ll mod=1e9+7;
#define rep(i,a) for (ll i=0;i<a;i++)
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> ll LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> ll UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,const T &b){if(a>b){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,const T &b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
void yneos(bool a){if(a) cout<<"Yes\n"; else cout<<"No\n";}



//  rainy ~ 雨に打たれて ~
int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	
	int n;
	cin>>n;
	vector<ll> p(n);
	rep(i,n) cin>>p[i];
	ll rev_2=(mod+1)/2;
	ll rev_3=(mod+1)/3;
	rep(i,n-2) p[i+1]=(p[i+1]*rev_3)%mod;
	p[n-1]=(p[n-1]*rev_2)%mod;
	ll ans=0;
	rep(i,n){
		if(i!=0) p[i]=(p[i-1]*p[i])%mod;
		ans+=p[i];
		ans%=mod;
		//cout<<(p[i]*6)%mod<<endl;
	}
	ans=(ans*2)%mod;
	rep(i,n-2) ans=(ans*3)%mod;
	cout<<ans<<"\n";
}