#include <bits/stdc++.h>
using namespace std;
#define sz(x) ((int)size(x))
#define all(x) begin(x), end(x)
#define trace(x) cout << #x << ": " << (x) << endl;
typedef long long ll;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r) { return (int) ((ll) rnd() % (r - l + 1)) + l; }
const int N = 100001;
ll mod = 1e9 + 7;
int h[N], R[N], L[N];
ll w[N];
ll pref[N];
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int n;
cin >> n;
for (int i = 1; i <= n; ++i) {
cin >> h[i];
}
for (int i = 1; i <= n; ++i) {
cin >> w[i];
}
int id = 1;
for (int i = 1; i <= n;) {
int j = i;
ll sum = 0;
while (j <= n && h[j] == h[i]) {
sum += w[j];
j += 1;
}
h[id] = h[i];
w[id] = sum;
++id;
i = j;
}
n = id - 1;
vector<int> st;
for (int i = 1; i <= n; ++i) {
while (!st.empty() && h[st.back()] > h[i]) {
R[st.back()] = i;
st.pop_back();
}
if (st.empty()) {
L[i] = 0;
} else {
L[i] = st.back();
}
st.push_back(i);
}
for (int x : st) {
R[x] = n + 1;
}
for (int i = 1; i <= n; ++i) {
pref[i] = pref[i - 1] + w[i];
}
ll ans = 0;
const ll inv2 = (mod + 1) / 2;
for (int i = 1; i <= n; ++i) {
ll sumR = (pref[R[i] - 1] - pref[i]) % mod;
ll sumL = (pref[i - 1] - pref[L[i]]) % mod;
ll x = (h[i] * (ll)(h[i] + 1)) / 2 % mod;
ll now = (sumR * (sumL + w[i])) % mod;
now = (now + (sumL + w[i]) * (sumL + w[i] + 1) % mod * inv2 % mod - sumL * (sumL + 1) % mod * inv2 % mod) % mod;
now = (now + mod) % mod;
ans = (ans + now * x) % mod;
}
cout << ans;
return 0;
}
