#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <vector>
#include <queue>
#include <stack>
typedef long long llong;
const int MAXN = 100000 + 10;
const int MOD = 1e9 + 7;
const int INF = 2e9;
int n;
llong h[MAXN];
llong w[MAXN];
int prev[MAXN];
int next[MAXN];
llong prefix[MAXN];
std::stack <int> st;
void solve()
{
for (int i = 1 ; i <= n ; ++i)
{
prefix[i] = prefix[i - 1] + w[i];
}
h[0] = h[n + 1] = 0;
st.push(0);
for (int i = 1 ; i <= n ; ++i)
{
while (h[st.top()] > h[i])
{
st.pop();
}
prev[i] = st.top();
st.push(i);
}
while (st.size()) st.pop();
st.push(n + 1);
for (int i = n ; i >= 1 ; --i)
{
while (h[st.top()] >= h[i])
{
st.pop();
}
next[i] = st.top();
st.push(i);
}
llong ans = 0;
for (int i = 1 ; i <= n ; ++i)
{
llong cntPrev = (prefix[i - 1] - prefix[prev[i]]) % MOD;
llong cntNext = (prefix[next[i] - 1] - prefix[i]) % MOD;
ans += ((cntPrev * cntNext) % MOD) * ((h[i] * (h[i] + 1) / 2) % MOD);
ans += ((cntPrev * w[i]) % MOD) * ((h[i] * (h[i] + 1) / 2) % MOD);
ans += ((cntNext * w[i]) % MOD) * ((h[i] * (h[i] + 1) / 2) % MOD);
ans += ((w[i] * (w[i] + 1) / 2) % MOD) * ((h[i] * (h[i] + 1) / 2) % MOD);
ans %= MOD;
}
std::cout << ans << '\n';
}
void input()
{
std::cin >> n;
for (int i = 1 ; i <= n ; ++i)
{
std::cin >> h[i];
}
for (int i = 1 ; i <= n ; ++i)
{
std::cin >> w[i];
}
}
void fastIOI()
{
std::ios_base :: sync_with_stdio(0);
std::cout.tie(nullptr);
std::cin.tie(nullptr);
}
int main()
{
fastIOI();
input();
solve();
return 0;
}
