#include <iterator>
#include <vector>
#include <iostream>
//#include <algorithm>
#include <numeric>
using namespace std;

void max_transform(vector<int> &vec);

int main() {
    size_t n;
    cin >> n;
    vector<int> data;
    while (n--) {
        int x;
        cin >> x;
        data.push_back(x);
    }
    max_transform(data);
    max_transform(data);
    size_t sum = accumulate(data.begin(), data.end(), 0,
                            [](const size_t &a, const size_t &b)
                            { return (a + b) % 1000000007; }
                           );
    cout << sum << endl;
    return 0;
}

void max_transform(vector<int> &vec)
{
    size_t len = vec.size();
    for (size_t k = 1; k < len; k++) {
        for (size_t i = 0; i < len - k; i++) {
            int max = vec[(k - 1) * (len - (k - 2) / 2) + i];
            if (max < vec[k + i])
                max = vec[k + i];
            vec.push_back(max);
        }
    }
}