#include <bits/stdc++.h>
using namespace std;
const int maxN = 1e5 + 5;
const long long mod = 1e9 + 7;
int h[maxN], w[maxN], L[maxN], R[maxN], belong[maxN];
long long sum = 0, ans = 0, total[maxN];
long long cost(long long X) {
long long A = X, B = X + 1;
if (A % 2 == 0) A /= 2;
else B /= 2;
A %= mod; B %= mod;
return (A * B) % mod;
}
void Merge(int u, int v) {
sum = (sum - cost(total[u]) + mod) % mod;
sum = (sum - cost(total[v]) + mod) % mod;
R[u] = R[v]; belong[R[u]] = u;
total[u] += total[v];
sum = (sum + cost(total[u])) % mod;
}
long long chain(int l, int r) {
long long A = 1LL * r * (r + 1) / 2;
long long B = 1LL * (l - 1) * l / 2;
return (A - B) % mod;
}
bool cmp(pair<int, int> A, pair<int, int> B) {
if (A.first != B.first) return A.first > B.first;
return A.second < B.second;
}
vector<pair<int, int>> event;
int main() {
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int n;
cin >> n;
for (int i = 1; i <= n; i++) {
cin >> h[i];
event.push_back({h[i], i});
}
for (int i = 1; i <= n; i++)
cin >> w[i];
for (int i = 1; i <= n; i++) {
L[i] = i;
R[i] = i;
}
sort(event.begin(), event.end(), cmp);
int prev_height = 1e9, i = 0;
while (i < event.size()) {
int curr_height = event[i].first;
ans = (ans + sum * chain(curr_height + 1, prev_height)) % mod;
while (i < event.size() && curr_height == event[i].first) {
int p = event[i].second; belong[p] = p; total[p] = w[p]; sum = (sum + cost(w[p])) % mod;
if (belong[p - 1]) Merge(belong[p - 1], belong[p]);
if (belong[p + 1]) Merge(belong[p], belong[p + 1]);
i++;
}
prev_height = curr_height;
}
ans = (ans + 1LL * sum * chain(1, prev_height)) % mod;
cout << ans;
return 0;
}
