#include<bits/stdc++.h>
const int MOD = int(1e9) + 7;
const int64_t INV_2 = 500000004;
int64_t f(int a, int b){
assert(a>=0);
assert(b>=0);
int res = int64_t(a) * (a + 1) % MOD * INV_2 % MOD * int64_t(b) % MOD * (b + 1) % MOD * INV_2 % MOD;
//~ assert(res >= 0);
return res;
}
int main(){
using namespace std;
ios::sync_with_stdio(false), cin.tie(nullptr);
int n;
cin >> n;
vector<int> h(n), w(n);
int all_1 = 1;
for(int i = 0;i < n;i++) cin >> h[i];
for(int i = 0;i < n;i++) {
cin >> w[i];
all_1 &= (w[i] == 1);
}
int64_t ans = 0;
vector<int64_t> psw(n);
for(int i = 0;i < n;i++){
psw[i] = w[i] + (i > 0 ? psw[i - 1] : 0);
}
vector<int> lew(n), praw(n);
// lew[i] I CARE ABOUT FIRST < ME
vector<int> st;
for(int i = 0;i < n;i++){
while(!st.empty() && h[st.back()] >= h[i]) st.pop_back();
lew[i] = (!st.empty() ? st.back()+1 : 0);
st.push_back(i);
}
st.clear();
for(int i = n - 1;i >= 0;i--){
while(!st.empty() && h[st.back()] > h[i]) st.pop_back();
praw[i] = (!st.empty() ? st.back()-1 : n-1);
st.push_back(i);
}
for(int i = 0;i < n;i++){
int64_t sL = 0;
int64_t sR = 0;
int l = lew[i];
int r = praw[i];
/*
while(l - 1 >= 0 && h[l - 1] >= h[i]){
l -= 1;
sL += w[l];
}
while(r + 1 < n && h[r + 1] > h[i]){
r += 1;
sR += w[r];
}
*/
//~ cerr << "i: " << i << " l: " << l << " r: " << r << endl;
sL = psw[i] - (l > 0 ? psw[l-1] : 0) - w[i];
sR = psw[r] - psw[i];
// but it must strictly contain me
assert(sL>=0);
assert(sR>=0);
sL %= MOD;
sR %= MOD;
if(w[i] == 1){
ans += f(h[i], w[i]) * int64_t(sL+1) % MOD * int64_t(sR+1) % MOD;
ans %= MOD;
}
else {
// w[i] > 1
// 1) touching with left side
ans += (w[i] - 1) * 1ll * (sL+1) % MOD * f(h[i], 1) % MOD;
ans %= MOD;
// 2) touching with the right side
ans += (w[i] - 1) * 1ll * (sR+1) % MOD * f(h[i], 1) % MOD;
ans %= MOD;
// 3) touching both sides
ans += f(h[i],1) * 1ll * (sR+1) % MOD * (sL+1) % MOD;
ans %= MOD;
// 4) not touching any side
if(w[i] > 2){
ans += f(h[i], w[i] - 2) % MOD;
ans %= MOD;
}
}
}
cout << ans%MOD << '\n';
return 0;
}
