#include <bits/stdc++.h>
using namespace std;
const long long mod = 1e9 + 7;
const int MaxN = 1e6 + 5;
int n;
pair<long long, long long> arr[MaxN];
void Inp()
{
cin >> n;
for (int x = 1; x <= n; x++)
{
cin >> arr[x].first;
}
for (int x = 1; x <= n; x++)
{
cin >> arr[x].second;
}
}
int root;
pair<int, int> child[MaxN];
void BuildTree()
{
for (int x = 1; x <= n; x++)
{
child[x] = make_pair(-1, -1);
}
stack<int> st;
for (int x = 1; x <= n; x++)
{
int pre = -1;
while (!st.empty() && arr[st.top()].first > arr[x].first)
{
pre = st.top();
st.pop();
}
child[x].first = pre;
if (!st.empty())
{
child[st.top()].second = x;
}
else
{
root = x;
}
st.push(x);
}
}
long long val[MaxN];
long long DFS(int u)
{
long long res = 0, a = (arr[u].first * (arr[u].first + 1) / 2) % mod, b = arr[u].second % mod;
if (~child[u].first && ~child[u].second)
{
res = (res + DFS(child[u].first)) % mod;
res = (res + DFS(child[u].second)) % mod;
long long c = (val[child[u].first] + b) % mod, d = (val[child[u].second] + b) % mod;
res = (res + c * d % mod * a % mod) % mod;
res = (res - (arr[u].second * (arr[u].second - 1) / 2) % mod * a % mod) % mod;
val[u] = (c + d - b) % mod;
return res;
}
if (~child[u].first)
{
res = DFS(child[u].first);
long long c = (val[child[u].first] + b) % mod;
res = (res + c * b % mod * a % mod) % mod;
res = (res - (arr[u].second * (arr[u].second - 1) / 2) % mod * a % mod) % mod;
val[u] = c;
return res;
}
if (~child[u].second)
{
res = DFS(child[u].second);
long long c = (val[child[u].second] + b) % mod;
res = (res + c * b % mod * a % mod) % mod;
res = (res - (arr[u].second * (arr[u].second - 1) / 2) % mod * a % mod) % mod;
val[u] = c;
return res;
}
res = (arr[u].second * (arr[u].second + 1) / 2) % mod * a % mod;
val[u] = b;
return res;
}
void Exc()
{
BuildTree();
long long res = DFS(root);
cout << (res % mod + mod) % mod;
}
int main()
{
//freopen("FANCYFENCE.INP", "r", stdin);
//freopen("FANCYFENCE.OUT", "w", stdout);
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int test = 1;
//cin >> test;
for (int x = 1; x <= test; x++)
{
Inp();
Exc();
}
return 0;
}
