#include <bits/stdc++.h>
#define ll long long
#define lll __int128_t
#define mp make_pair
using namespace std;
const int lim = 1e5 + 5;
int mod = 1e9 + 7;
ll res = 0;
ll mul(ll a, ll b) {
return (a * b) % mod;
}
lll mul(lll a, lll b) {
a %= mod;
b %= mod;
return (a * b) % mod;
}
ll powmod(ll a, ll b) {
if(b == 0)
return 1;
else {
ll tmp = powmod(a, b >> 1);
tmp = (tmp * tmp) % mod;
return b & 1 ? (tmp * a) % mod : tmp;
}
}
lll sum(lll x) {
if(x % 2 == 0)
return mul(x / 2, x + 1);
else
return mul(x, (x + 1) / 2);
}
ll sum(ll l, ll r) {
//cout << "QUERY " << l << " " << r << endl;
if(l > r)
return 0;
lll ret = sum(r) - sum(l - 1);
ret %= mod;
if(ret < 0)
ret += mod;
//cout << l << " " << r << " " << ret << endl;
return ret;
}
struct disjoint_set {
int h[lim], sz[lim];
ll a[lim], lh[lim];
disjoint_set() {
memset(h, -1, sizeof(h));
memset(a, 0, sizeof(a));
fill(sz, sz + lim, 1);
// lh diisi manual
}
int fh(int nd) {
return h[nd] == -1 ? nd : h[nd] = fh(h[nd]);
}
void merge(int x, int y) {
x = fh(x), y = fh(y);
if(x != y) {
int nh = min(lh[x], lh[y]);
res += mul(sum(nh + 1, lh[x]), sum(1, a[x])) + mul(sum(nh + 1, lh[y]), sum(1, a[y]));
h[y] = x;
sz[x] += sz[y];
a[x] += a[y];
lh[x] = nh;
}
}
};
int main() {
// use dsu, merging segments get count
// tiap segment simpan l, r, last_height
// nanti di calculate internal last_heightnya berapa
// di calculate merge last_heightnya berapa
int n;
cin >> n;
int h[n + 1], w[n + 1];
disjoint_set dsu;
for(int i = 1; i <= n; ++i) {
cin >> h[i];
dsu.lh[i] = h[i];
}
for(int i = 1; i <= n; ++i) {
cin >> w[i];
dsu.a[i] = w[i];
}
priority_queue<pair<int, int>> pq;
for(int i = 1; i <= n; ++i) {
if(i != 1 && h[i - 1] >= h[i]) {
pq.push(mp(h[i], i));
}
if(i != n && h[i + 1] >= h[i]) {
pq.push(mp(h[i], i + 1));
}
}
// merge dr large to small
// dr height tertinggi ke height terendah?
while(pq.size()) {
int mg = pq.top().second;
pq.pop();
dsu.merge(mg, mg - 1);
}
ll a = dsu.a[dsu.fh(1)], lh = dsu.lh[dsu.fh(1)];
//cout << a << " " << lh << endl;
res += mul(sum(1, lh), sum(1, a));
res %= mod;
cout << res << endl;
}
