#include<bits/stdc++.h>
using namespace std;
template <long long MOD = 1000000007, typename T = int> struct modint {
T x;
modint() : x(0) {}
modint(int64_t y) : x(y >= 0 ? y % MOD : (MOD - (-y) % MOD) % MOD) {}
modint &operator+=(const modint &p) {
if ((x += p.x) >= MOD) x -= MOD;
return *this;
}
modint &operator-=(const modint &p) {
if ((x += MOD - p.x) >= MOD) x -= MOD;
return *this;
}
modint &operator*=(const modint &p) {
x = (int)(1LL * x * p.x % MOD);
return *this;
}
modint &operator/=(const modint &p) {
*this *= p.inv();
return *this;
}
modint operator-() const { return modint(-x); }
modint operator+(const modint &p) const { return modint(*this) += p; }
modint operator-(const modint &p) const { return modint(*this) -= p; }
modint operator*(const modint &p) const { return modint(*this) *= p; }
modint operator/(const modint &p) const { return modint(*this) /= p; }
bool operator==(const modint &p) const { return x == p.x; }
bool operator!=(const modint &p) const { return x != p.x; }
modint inv() const {
T a = x, b = MOD, u = 1, v = 0, t;
while (b > 0) {
t = a / b;
swap(a -= t * b, b);
swap(u -= t * v, v);
}
return modint(u);
}
modint pow(int64_t n) const {
modint ret(1), mul(x);
while (n > 0) {
if (n & 1) ret *= mul;
mul *= mul;
n >>= 1;
}
return ret;
}
friend ostream &operator<<(ostream &os, const modint &p) { return os << p.x; }
friend istream &operator>>(istream &is, modint &a) {
int64_t t;
is >> t;
a = modint<MOD>(t);
return (is);
}
T val() const { return x; }
static constexpr T mod() { return MOD; }
static constexpr T half() { return (MOD + 1) >> 1; }
};
//--
using Mint = modint<1000000007>;
int main(){
cin.tie(0)->sync_with_stdio(0);
int n;
cin >> n;
vector<long long> h(n + 1);
for(int i = 1;i <= n;i ++){
cin >> h[i];
}
vector<Mint> w(n + 1);
for(int i = 1;i <= n;i ++){
cin >> w[i];
}
vector<int> L(n + 1);
for(int i = 1;i <= n;i ++){
L[i] = i - 1;
while(L[i] > 0 && h[i] < h[L[i]]){
L[i] = L[L[i]];
}
}
vector<int> R(n + 1);
for(int i = n;i >= 1;i --){
R[i] = i + 1;
while(R[i] <= n && h[i] <= h[R[i]]){
R[i] = R[R[i]];
}
}
Mint ans = 0;
vector<Mint> sum(n + 1);
for(int i = 1;i <= n;i ++){
sum[i] = sum[i - 1] + w[i];
}
for(int i = 1;i <= n;i ++){
ans += w[i] * (w[i] + 1) * Mint(h[i]) * Mint(h[i] + 1) / 4;
ans += ((sum[i] - sum[L[i]]) * (sum[R[i] - 1] - sum[i - 1]) - w[i] * w[i]) * Mint(h[i]) * Mint(h[i] + 1) / 2;
}
cout << ans << '\n';
}
