#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1e9 + 7;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
long long n;
cin >> n;
vector<long long> h(n), w(n);
for (int i = 0; i < n; i++) {
cin >> h[i];
}
for (int i = 0; i < n; i++) {
cin >> w[i];
}
// Subtask 3: all heights are equal, so h[0] is the common height.
long long totalwidth = 0;
for (int i = 0; i < n; i++){
totalwidth += w[i];
totalwidth %= MOD; // optional: to keep the number smaller if widths are huge
}
// Using __int128 to avoid overflow in multiplication.
__int128 t = totalwidth;
long long n1 = (long long)((t * (t + 1)) % MOD);
__int128 h_val = h[0];
long long n2 = (long long)((h_val * (h_val + 1)) % MOD);
long long inv4 = 250000002; // Modular inverse of 4 mod MOD
long long ans = ((n1 * n2) % MOD * inv4) % MOD;
cout << ans;
return 0;
}
