#include <iostream>
#include <vector>
#define llong long long
using namespace std;


const llong mod=int(1e9)+7;

int main(){
    llong n;
    cin >> n;
    vector<llong>a(n);
    for(int i=0; i<n; i++)cin >> a[i];
    llong c=1;
    llong ret=0;
    for(int i=0; i<n; i++){
        ret+=a[i]*c;
        ret%=mod;
        c=(c*(n-i-1)/(llong)(i+1))%mod;
    }
    cout << ret;
    return 0;
}