// Author: _Sherbiny
#include "bits/stdc++.h"
using namespace std;
#ifdef DBG
#include "./debug.h"
#else
#define dbg(...)
#endif
typedef long long ll;
#define endl '\n'
#define int ll
//==================//
vector<int> nextSmaller(vector<int> &v) {
int n = v.size();
vector<int> res(n, n);
stack<int> st;
for (int i = 0; i < n; ++i) {
if (st.empty() || v[i] >= v[st.top()]) st.push(i);
else {
res[st.top()] = i;
st.pop();
--i;
}
}
return res;
}
vector<int> prevSmaller(vector<int> &v) {
int n = v.size();
vector<int> res(n, -1);
stack<int> st;
for (int i = n - 1; i >= 0; --i) {
// you may need to remove the equal
if (st.empty() || v[i] > v[st.top()]) st.push(i);
else {
res[st.top()] = i;
st.pop();
++i;
}
}
return res;
}
const int mod = 1e9 + 7;
void magic() {
int n; cin >> n;
vector<int> h(n + 1), w(n + 1), p(n + 1);
for(int i = 1; i <= n; ++i) cin >> h[i];
for(int i = 1; i <= n; ++i) cin >> w[i], p[i] += w[i] + p[i - 1];
vector<int> nxt = nextSmaller(h);
vector<int> prv = prevSmaller(h);
int res = 0;
for(int i = 1; i <= n; ++i) {
int ver = h[i] * (h[i] + 1) / 2 % mod;
int before = (p[i - 1] - p[prv[i]]) % mod;
int after = (p[nxt[i] - 1] - p[i]) % mod;
res += after * before % mod * ver % mod;
res += w[i] * before % mod * ver % mod;
res += w[i] * after % mod * ver % mod;
res += w[i] * (w[i] + 1) / 2 % mod * ver % mod;
res %= mod;
}
cout << res << endl;
}
signed main() {
ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
int t = 1;
while (t--) magic();
}
