a.cpp

#include <bits/stdc++.h>
int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(0);
    const int mod = (int)1e9+7;
    int n, answ = 0;
    std::cin >> n;
    for (int i = 0; i < n; i++) {
        int64_t a;
        std::cin >> a;
        if (a < 0) { a = mod - (-a) % mod; }
        else if (a >= mod) { a %= mod; }
        answ += int(a);
        if (answ >= mod) { answ -= mod; }
    }
    std::cout << answ << std::endl;
    return 0;
}