# include <bits/stdc++.h>
using namespace std;
# define ld long double
# define int long long
# define SNC cin.tie(0) -> ios::sync_with_stdio(false)
# define For(i, a, b) for (int i = a; i <= b; i++)
# define Rep(i, b, a) for (int i = b; i >= a; i--)
# define Fa(i, x) for (auto i : x)
# define ii pair<int, int>
# define iii pair<int, ii>
# define iv pair<ii, ii>
# define f first
# define s second
# define all(x) x.begin(), x.end()
# define sp(x) setprecision(x) << fixed
# define name "FENCE"
# define spc " "
# define endl "\n"
void readfile(){
if (fopen(name".INP", "r")){
freopen(name".INP", "r", stdin);
freopen(name".OUT", "w", stdout);
}
}
const int mod = 1e9 + 7;
const int inf = 1e18;
const int N = 2e5 + 10;
typedef int arr[N];
typedef vector<int> vi;
typedef vector<ii> vii;
int n;
arr h, w;
void Input(){
cin >> n;
For(i, 1, n)
cin >> h[i];
For(i, 1, n)
cin >> w[i];
}
int add(int a, int b){
return (a % mod + b % mod) % mod;
}
int sub(int a, int b){
return (a % mod - b % mod + mod) % mod;
}
int mul(int a, int b){
return ((a % mod) * (b % mod)) % mod;
}
int div(int a){
int b = (a + 1);
if (b % 2 == 0)
b /= 2;
else a /= 2;
return mul(a, b);
}
namespace sub1{
bool approved(){
return n <= 1000;
}
arr _h;
void Solve(){
}
}
namespace sub2{
bool approved(){
For(i, 1, n)
if (h[i] != h[1])
return false;
return true;
}
void Solve(){
int W = 0, H = h[1];
For(i, 1, n)
W += w[i];
cout << mul(div(H), div(W)) % mod;
}
}
namespace sub3{
bool approved(){
For(i, 2, n)
if (h[i - 1] > h[i])
return false;
return true;
}
arr pre;
int ans = 0;
void Solve(){
int W = 0;
Rep(i, n, 1)
W += w[i];
int sum = 0;
For(i, 1, n){
// (ans += (h[i] * (h[i] + 1) / 2) * (W * (W + 1) / 2));
ans = add(ans, mul(div(h[i]), div(W)));
sum = W;
W -= w[i];
// (ans -= (h[i - 1] * (h[i - 1] + 1) / 2) * (sum * (sum + 1) / 2));
ans = sub(ans, mul(div(h[i - 1]), div(sum)));
}
cout << ans;
}
}
void Solve(){
if (sub2::approved())
sub2::Solve();
else if (sub3::approved())
sub3::Solve();
}
signed main(){
SNC;
readfile();
Input();
Solve();
return 0;
}
