#include <bits/stdc++.h>
using namespace std;
#define int long long
const int maxn = 1e5 + 5, mod = 1e9 + 7, inv2 = 5e8 + 4;
int pre[maxn], h[maxn], w[maxn], l[maxn], r[maxn];
int cnt(int x, int y){
return x * (x + 1) % mod * inv2 % mod * y % mod * (y + 1) % mod * inv2;
}
void solve(){
int n; cin >> n;
for(int i = 1; i <= n; i++) cin >> h[i];
for(int i = 1; i <= n; i++) cin >> w[i];
vector<int> st;
for(int i = 1; i <= n; i++){
while(st.size() && h[st.back()] >= h[i]) st.pop_back();
l[i] = (st.size() ? st.back() : 0);
st.push_back(i);
}
st.clear();
for(int i = n; i >= 1; i--){
while(st.size() && h[st.back()] > h[i]) st.pop_back();
r[i] = (st.size() ? st.back() : n + 1);
st.push_back(i);
}
for(int i = 1; i <= n; i++) pre[i] = pre[i - 1] + w[i];
int res = 0;
for(int i = 1; i <= n; i++){
int ll = l[i] + 1, rr = r[i] - 1;
res = (res + cnt(pre[rr] - pre[ll - 1], h[i]) - cnt(pre[i - 1] - pre[ll - 1], h[i]) - cnt(pre[rr] - pre[i], h[i])) % mod;
}
cout << (res + mod) % mod;
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
solve();
}
