//Proud of You//
#include <bits/stdc++.h>
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
using namespace std;
const int N = 1e5 + 17, M = 1e9 + 7;
int n, r[N], w[N], ans;
pair <int, int> a[N];
bool ex[N];
inline int root (int u)
{
if (u == r[u])
{
return u;
}
return r[u] = root(r[u]);
}
inline bool join (int x, int y)
{
int rx = root(x), ry = root(y);
if (rx == ry)
{
return 0;
}
r[ry] = rx, w[rx] += w[ry];
return 1;
}
inline int c2n (int x)
{
return 1LL * x * (x - 1) / 2 % M;
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> n;
for (int i = 1, h; i <= n; ++i)
{
cin >> h;
a[i] = {h, i};
}
for (int i = 1; i <= n; ++i)
{
cin >> w[i];
r[i] = i;
}
sort (a + 1, a + n + 1, greater<>());
for (int j = 1; j <= n; ++j)
{
auto [h, i] = a[j];
ex[i] = 1;
if (ex[i - 1])
{
join (i - 1, i);
}
if (ex[i + 1])
{
join (i, i + 1);
}
i = root(i);
ans = (ans + 1LL * c2n (w[i] + 1) * h) % M;
}
cout << ans;
}
