#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
long long MOD = 1000000007;
int main(){
    //想定TLE3 (O(N^2))
    long long N;
    cin >> N;
    vector<int> A(N);
    for (int i = 0; i < N; i++){
        cin >> A[i];
    }
    vector<long long> S(N + 1, 0);
    for (int i = 0; i < N; i++){
        S[i + 1] = S[i] + A[i];
        if (S[i + 1] >= MOD){
            S[i + 1] -= MOD;
        }
    }
    long long ans = 0;
    for (int i = 0; i < N; i++){
        for (int j = i; j < N; j++){
            ans += S[j + 1] - S[i] + MOD;
            while (ans >= MOD){
                ans -= MOD;
            }
        }
    }
    cout << ans << endl;
}