#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll mod = 1e9 + 7;
ll solve_rect(ll h, ll w) {
h %= mod;
w %= mod;
ll hc = (h * (h + 1) / 2) % mod;
ll wc = (w * (w + 1) / 2) % mod;
return (hc * wc) % mod;
}
int main() {
ios::sync_with_stdio(0), cin.tie(0);
int n;
cin >> n;
set<pair<ll, int>> height_index_set;
map<int, pair<ll, ll>> index_dim_map;
height_index_set.insert({0, -1});
height_index_set.insert({0, n});
index_dim_map[-1] = {0, 0};
index_dim_map[n] = {0, 0};
{
vector<ll> hv(n), wv(n);
for (ll& h : hv) cin >> h;
for (ll& w : wv) cin >> w;
for (int i = 0; i < n; i++) {
if (i != n + 1 && hv[i] == hv[i + 1]) {
wv[i + 1] += wv[i];
continue;
}
index_dim_map[i] = {hv[i], wv[i]};
height_index_set.insert({-hv[i], i});
}
}
ll res = 0;
while (height_index_set.size() > 1) {
auto _it = height_index_set.begin();
int ind_curr = _it->second;
height_index_set.erase(_it);
// should always be the iterator at key ind_curr
auto curr_it = index_dim_map.lower_bound(ind_curr);
auto& [h_curr, w_curr] = index_dim_map[ind_curr];
assert(curr_it->first == ind_curr);
auto next_it = curr_it;
next_it++;
auto& [h_next, w_next] = next_it->second;
auto prev_it = curr_it;
prev_it--;
auto& [h_prev, w_prev] = prev_it->second;
assert(h_curr > h_prev);
assert(h_curr > h_next);
res += solve_rect(h_curr, w_curr);
res %= mod;
if (h_prev > h_next) {
res -= solve_rect(h_prev, w_curr);
res += mod;
res %= mod;
w_prev += w_curr;
w_prev %= mod;
}
else if (h_next > h_prev) {
res -= solve_rect(h_next, w_curr);
res += mod;
res %= mod;
w_next += w_curr;
w_next %= mod;
}
else {
res -= solve_rect(h_prev, w_curr);
res += mod;
res %= mod;
w_prev += w_curr + w_next;
w_prev %= mod;
height_index_set.erase({-h_next, next_it->first});
index_dim_map.erase(next_it);
}
index_dim_map.erase(curr_it);
}
assert(height_index_set.size() == 1);
assert(index_dim_map.size() == 1);
cout << res;
}
