//
// Created by liasa on 11/11/2025.
//
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define vll vector<ll>
const ll mod = 1e9 + 7;
ll pw(ll a, ll b) {
ll ans = 1;
while (b) {
if (b & 1) {
ans = (ans * a) % mod;
b--;
}
b /= 2;
a = (a * a) % mod;
}
return ans;
}
ll invi(ll x) { return pw(x, mod - 2); }
ll mul(ll a, ll b) { return (ll)((__int128)a * b % mod); }
ll addi(ll H, ll W) {
H++;
W++;
ll a = mul(H % mod, (H - 1) % mod);
ll b = mul(W % mod, (W - 1) % mod);
ll inv2 = invi(2);
ll ans = mul(mul(a, b), mul(inv2, inv2));
return ans;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
ll n;
cin >> n;
vll h(n), w(n);
vll pre(n + 2);
for (ll i = 0; i < n; ++i) {
cin >> h[i];
}
for (ll i = 0; i < n; ++i) {
cin >> w[i];
pre[i + 1] = pre[i] + w[i];
}
vll left(n);
stack<ll> s;
for (ll i = 0; i < n; ++i) {
while (!s.empty() && h[s.top()] >= h[i])
s.pop();
left[i] = s.empty() ? 0 : s.top() + 1;
s.push(i);
}
while (!s.empty())
s.pop();
vll right(n);
for (ll i = n - 1; i >= 0; --i) {
while (!s.empty() && h[s.top()] > h[i])
s.pop();
right[i] = s.empty() ? n : s.top() + 1;
s.push(i);
}
ll ans = 0;
auto sumi = [&pre](ll l, ll r) -> ll {
return (l > r) ? 0 : pre[r + 1] - pre[l];
};
for (ll i = 0; i < n; ++i) {
ll L = sumi(left[i], i - 1);
ll C = w[i];
ll R = sumi(i + 1, right[i] - 1);
ll T = (L + C + R) % mod;
ll vert = addi(1, h[i]);
ll hori = (addi(1, T) - addi(1, L) - addi(1, R)) % mod;
if (hori < 0)
hori += mod;
ans = (ans + mul(vert, hori)) % mod;
}
cout << ans;
}
