#include<bits/stdc++.h>
using namespace std;
#define int long long
#define endl "\n"
#define pii pair<int,int>
#define pis pair<string,int>
#define psi pair<int,string>
#define umap unordered_map
const int mod = 1e9 + 7;
int ai[300000];
void miss() {
    int n;
    int qwq = 0;
    while(cin >> n) {
    for(int i = 1; i <= n; i++) cin >> ai[i];
    int qwq = 0,qaq = 0,qqq = 0;
    for(int i = 2; i <= n; i++) {
        qwq = qwq + ai[i];
        qaq = qaq + (ai[i] % mod * ai[i] % mod);
        qqq = qqq + (ai[i] % mod * ai[i] % mod * ai[i] % mod);
        qwq = qwq % mod;
        qaq = qaq % mod;
        qqq = qqq % mod;
    }
    int ans = 0;
    for(int i = 1; i <= n; i++) {
        ans = ans + (ai[i] % mod * (qwq * qwq * qwq - 3 * qaq * qwq + 2 * qqq) % mod) % mod / 6;
        ans = ans % mod;
        qwq = qwq - ai[i + 1];
        qaq = qaq - ai[i + 1] * ai[i + 1];
        qqq = qqq - ai[i + 1] * ai[i + 1] * ai[i + 1];
        if(qwq < 0) qwq += mod;
        if(qaq < 0) qaq += mod;
        if(qqq < 0) qqq += mod;
    }
    cout << ans % mod << endl;
    }
}
signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0),cout.tie(0);

    int n = 1;
    //cin >> n;
    while(n--) miss();
}