#include<bits/stdc++.h>
#define pb push_back
using namespace std;
typedef long long ll;
const int N = 1e5 + 10, MOD = 1e9 + 7;
int power(int a, int b) {
if(b == 0)
return 1;
int res = power(a, b / 2);
res = 1LL * res * res % MOD;
if(b & 1) res = 1LL * res * a % MOD;
return res;
}
int two = power(2, MOD - 2);
int C2(int a) { return 1LL * a * (a - 1) % MOD * two % MOD; }
int H[N], W[N], L[N], PS[N], M[N], len[N], n;
ll ans;
int main(){
ios::sync_with_stdio(0);
cin.tie(0), cout.tie(0);
cin >> n;
for(int i = 1; i <= n; i++)
cin >> H[i];
for(int i = 1; i <= n; i++)
cin >> W[i], PS[i] = (W[i] + PS[i - 1]) % MOD;
stack<int> st;
for(int i = 1; i <= n; i++) {
while(!st.empty() and H[i] <= H[st.top()]) st.pop();
L[i] = ((int) st.size() > 0 ? st.top() + 1 : 1);
if(!st.empty()) M[i] = max(M[i], H[st.top()]);
st.push(i);
}
st = stack<int>();
for(int i = n; i >= 1; i--) {
while(!st.empty() and H[i] < H[st.top()]) st.pop();
len[i] = (PS[((int) st.size() > 0 ? st.top() - 1 : n)] - PS[L[i] - 1] + MOD) % MOD;
if(!st.empty()) M[i] = max(M[i], H[st.top()]);
st.push(i);
}
for(int i = 1; i <= n; i++)
ans += 1LL * C2(H[i] + 1) * C2(1 + (len[i])) % MOD, ans %= MOD;
for(int i = 1; i <= n; i++)
ans -= 1LL * C2(M[i] + 1) * C2(1 + (len[i])) % MOD, ans = (ans + MOD) % MOD;
cout << ans << '\n';
return 0;
}
