#include <bits/stdc++.h>
using namespace std;
void setup()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
}
int n;
long long res, mod = 1e9 + 7, pre[100001], a, b, c, w[100001], h[100001];
set<array<long long, 3>> s;
array<long long, 3> temp;
pair<long long, long long> p[100001];
int main()
{
setup();
cin >> n;
for (int i = 1; i <= n; ++i)
{
cin >> h[i];
p[i] = {h[i], i};
}
for (int i = 1; i <= n; ++i)
{
cin >> w[i];
pre[i] = (pre[i - 1] + w[i]) % mod;
}
sort(p + 1, p + 1 + n);
s.insert({n, 1, 0});
for (int i = 1; i <= n; ++i)
{
temp = (*s.lower_bound({p[i].second, -1, -1}));
s.erase(temp);
a = (pre[temp[0]] - pre[temp[1] - 1] + mod) % mod;
a = (a * (a + 1) / 2) % mod;
b = (p[i].first * (p[i].first + 1) / 2 - temp[2] * (temp[2] + 1) / 2) % mod;
(res += a * b) %= mod;
if (p[i].second > temp[1])
{
s.insert({p[i].second - 1, temp[1], p[i].first});
}
if (p[i].second < temp[0])
{
s.insert({temp[0], p[i].second + 1, p[i].first});
}
}
cout << res;
return 0;
}
