#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define pb push_back

const ll mod = 1e9 + 7;

void solve() {
    ll n;
    cin >> n;
    vector<ll> height(n, 0ll);
    vector<ll> width(n, 0ll);
    for(ll &x : height) cin >> x;
    for(ll &x : width) cin >> x;
    ll ans = 0;
    for(ll i = 0; i < n; ++i) {
        ll cur_height = height[i];
        ll temp_height = ((cur_height * (cur_height + 1)) / 2) % mod;
        ll temp_width = ((width[i] * (width[i] + 1)) / 2) % mod;
        ans += (temp_width * temp_height) % mod;
        ans %= mod;
        for(ll j = i + 1; j < n; ++j) {
            cur_height = min(cur_height, height[j]);
            temp_width = (width[i] * width[j]) % mod;
            temp_height = ((cur_height * (cur_height + 1)) / 2) % mod;
            ans += (temp_width * temp_height) % mod;
            ans %= mod;
        }
    }
    cout << ans << "\n";
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    solve();
    return 0;
}