#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;

long long modc = 1e9+7;

long long mod_exp(long long b, long long e){
    if (e > 0 && b == 0) return 0;
    long long ans = 1;
    b %= modc;

    while (e > 0){
        if ((e & 1LL)) ans = (ans * b) % modc;
        e = e >> 1LL;
        b = (b*b) % modc;
    }

    return ans;
}

int main(){

    int N;
    long long S=0, S2=0, ans=0;
    cin >> N;
    assert(N <= 100000);
    vector<long long> A(N);

    for (int i=0; i<N; i++){
        cin >> A[i];
        S += A[i];
        S2 += (A[i]*A[i]) % modc;
        S2 %= modc;
        assert(1 <= A[i]);
    }

    assert(S <= 1e9);

    ans = ((S*S) % modc + modc - S2) % modc;
    ans = (ans * mod_exp(S, modc-2)) % modc;
    ans = (ans + 1) % modc;

    cout << ans << endl;

    return 0;
}