#include <bits/stdc++.h>
#define ll long long
using namespace std;
const ll mod = 1e9+7;
ll poww(ll x, ll y) {
if (y == 0) return 1;
ll k = poww(x, y/2);
k *= k, k %= mod;
if (y % 2 == 1) k *= x, k %= mod;
return k;
}
ll inv(ll x) { return poww(x, mod-2); }
int main() {
ios::sync_with_stdio(0), cin.tie(0);
int n;
cin >> n;
ll h[n], w[n];
for (auto &e : h) cin >> e;
for (auto &e : w) cin >> e;
stack <pair <ll, ll>> st;
ll curr = 0, ans = 0;
auto calc = [&] (ll h, ll w) {
return (((((h * (h+1)) % mod) * w) % mod) * inv(2)) % mod;
};
auto calc2 = [&] (ll h, ll w) {
ll P = ((((h * (h+1)) % mod) * inv(2)) % mod);
ll Q = ((((w * (w+1)) % mod) * inv(2)) % mod);
return (P * Q) % mod;
};
for (int i = 0; i < n; i++) {
ll nw = w[i];
while (st.size() && st.top().first >= h[i]) {
auto [H, W] = st.top(); st.pop();
curr -= calc(H % mod, W % mod); curr %= mod, curr += mod, curr %= mod;
curr += calc(h[i] % mod, W % mod); curr %= mod;
nw += W;
}
ans += (curr * (w[i] % mod)) % mod, ans %= mod;
ans += calc2(h[i] % mod, w[i] % mod), ans %= mod;
curr += calc(h[i] % mod, w[i] % mod), curr %= mod;
st.emplace(h[i], nw);
}
cout << ans << '\n';
}
