#include <bits/stdc++.h>
using namespace std;
#define ll long long
constexpr ll MOD = 1e9 + 7;
int solve(int N, vector<int> L, vector<int> W) {
ll res = 0;
// individual
for (int i = 0; i < N; i ++) {
ll w = W[i];
ll h = L[i];
ll horiz = ((h * (h + 1)) / 2) % MOD;
ll vertic = ((w * (w + 1)) / 2) % MOD;
ll curr = (horiz * vertic) % MOD;
res = (res + curr) % MOD;
}
// invariante: decrescente second
stack<pair<ll, ll>> s; // width, (height + 1) choose 2
ll curr_sum = 0;
for (int i = 0; i < N; i ++) {
ll w = W[i];
ll new_h = L[i];
ll sostituiti = 0;
ll to_remove = 0;
ll to_add = 0;
while (!s.empty() && s.top().second > new_h) {
ll d = ((s.top().second * (s.top().second + 1)) / 2) % MOD;
d = (d * s.top().first) % MOD;
to_remove = (to_remove + d) % MOD;
sostituiti = (sostituiti + s.top().first) % MOD;
s.pop();
}
if (sostituiti > 0) s.push({sostituiti, new_h});
to_add = ((new_h * (new_h + 1)) / 2) % MOD;
to_add = (to_add * sostituiti) % MOD;
curr_sum = (curr_sum - to_remove + MOD) % MOD;
curr_sum = (curr_sum + to_add) % MOD;
ll d = (curr_sum * w) % MOD;
res = (res + d) % MOD;
ll nuovo = ((new_h * (new_h + 1)) / 2) % MOD;
nuovo = (nuovo * w) % MOD;
curr_sum = (curr_sum + nuovo) % MOD;
s.push({w, new_h});
}
return res;
}
int main() {
int N;
cin >> N;
vector<int> L(N), W(N);
for(int &x: L) cin >> x;
for(int &x: W) cin >> x;
cout << solve(N, L, W) << "\n";
}
