/*
Code written by Talant I.D.
*/
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
#define precision(n) fixed << setprecision(n)
#define pb push_back
#define ub upper_bound
#define lb lower_bound
#define mp make_pair
#define eps (double)1e-9
#define PI 2*acos(0.0)
#define endl "\n"
#define sz(v) int((v).size())
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define do_not_disturb ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define OK cout << "OK" << endl;
const int mod = 1e9+7;
ll mode(ll a) {
a %= mod;
if (a < 0) a += mod;
return a;
}
ll subt(ll a, ll b) {
return mode(mode(a)-mode(b));
}
ll add(ll a, ll b) {
return mode(mode(a)+mode(b));
}
ll mult(ll a, ll b) {
return mode(mode(a)*mode(b));
}
ll binpow(ll a, ll b) {
ll res = 1;
while (b) {
if (b&1) res = mult(res, a);
a = mult(a, a);
b >>= 1;
}
return res;
}
const int N = 1e5+7;
ll h[N], w[N], dp[N];
int n;
int main() {
do_not_disturb
cin >> n;
for (int i = 1; i <= n; i++) {
cin >> h[i];
}
for (int i = 1; i <= n; i++) {
cin >> w[i];
}
stack <pii> st;
ll ans = 0;
ll sum = 0;
for (int i = 1; i <= n; i++) {
ll additional = 0;
while (!st.empty() && st.top().first > h[i]) {
additional = add(additional, st.top().second);
sum = subt(sum, mult(mult(st.top().first, st.top().first+1), mult(st.top().second, binpow(2, mod-2))));
st.pop();
}
ans = add(ans, mult(mult(mult(h[i], h[i]+1), mult(w[i], w[i]+1)), binpow(4, mod-2)));
ans = add(ans, mult(sum, w[i]));
ans = add(ans, mult(mult(additional, w[i]), mult(h[i], mult(h[i]+1, binpow(2, mod-2)))));
sum = add(sum, mult(mult(h[i], mult(h[i]+1, binpow(2, mod-2))), add(additional, w[i])));
st.push(mp(h[i], add(additional, w[i])));
}
cout << ans;
return 0;
}
