//Proud of You//
#include <bits/stdc++.h>
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#define int long long
using namespace std;
const int N = 1e5 + 17, M = 1e9 + 7;
int n, r[N], w[N], m[N], d2, ans;
pair <int, int> a[N];
bool ex[N], vi[N];
inline int lt (long long a, long long b)
{
a %= M;
if (!b)
{
return 1;
}
if (b == 1)
{
return a;
}
int z = lt (a, b / 2);
z = 1LL * z * z % M;
if (b & 1)
{
z = 1LL * z * a % M;
}
return z;
}
inline int c2n (int x)
{
return 1LL * x * (x - 1) % M * d2 % M;
}
inline int root (int u)
{
if (u == r[u])
{
return u;
}
return r[u] = root(r[u]);
}
inline bool join (int x, int y)
{
x = root(x), y = root(y);
if (x == y)
{
return 0;
}
r[y] = x, ans = (ans + 1LL * ((m[x] - m[y]) * m[x] % M - c2n (m[x] - m[y]) + M) * c2n (w[x] + 1)) % M;
w[x] = (w[x] + w[y]) % M, m[x] = min (m[x], m[y]);
return 1;
}
int32_t 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}, m[i] = h;
}
for (int i = 1; i <= n; ++i)
{
cin >> w[i];
r[i] = i;
}
sort (a + 1, a + n + 1, greater<>());
d2 = lt (2, M - 2);
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 + 1, i);
}
}
for (int i = 1; i <= n; ++i)
{
int r = root(i);
if (!vi[r])
{
vi[r] = 1;
ans = (ans + 1LL * c2n (m[r] + 1) * c2n (w[r] + 1)) % M;
}
}
cout << ans;
}
