#include <bits/stdc++.h>
#define all(v) begin(v), end(v)
#define ii pair<int, int>
#define fi first
#define se second
#define siz(v) (int)(v).size()
#define lli pair<long long, int>
#define BIT(x, i) (((x) >> (i)) & 1)
#define MASK(i) (1LL << (i))
using namespace std;
bool M1;
const int MAXN = 1e5 + 5, LOG = 62, MAXV = 1e6 + 6, infINT = 1e9 + 12312, mod = 1e9 + 7;
const long long inf = 1e18 + 132;
template<class X, class Y> bool minimize(X &x, const Y &y){return x > y ? x = y, 1: 0;}
template<class X, class Y> bool maximize(X &x, const Y &y){return x < y ? x = y, 1: 0;}
int mul(const int &a, const int &b){
assert(a < mod && b < mod);
return 1LL * a * 1LL * b % mod;
}
void add(int &a, const int &b){
assert(a < mod && b < mod);
a += b;
if (a >= mod) a -= mod;
}
void sub(int &a, const int &b){
assert(a < mod && b < mod);
a -= b;
if (a < 0) a += mod;
}
int numRect, height[MAXN], width[MAXN], f[MAXN], pre[MAXN];
int bin_pow(int a, int k){
int res = 1;
while(k){
if (k & 1) res = mul(res, a);
a = mul(a, a); k >>= 1;
}
return res;
}
void input(){
cin >> numRect;
for(int i = 1; i <= numRect; i++) cin >> height[i];
for(int i = 1; i <= numRect; i++) cin >> width[i];
}
int get(const int &L, const int &R){
int sum = 0;
add(sum, pre[R]);
sub(sum, pre[L - 1]);
return sum;
}
void solve(){
for(int i = 1; i <= numRect; i++){
pre[i] = pre[i - 1];
add(pre[i], width[i]);
}
int inv = bin_pow(2, mod - 2), res = 0, sum = 0;
stack<int > st;
for(int i = 1; i <= numRect; i++){
vector<int > can;
while(siz(st) && height[st.top()] > height[i]){
sub(sum, mul(mul(mul(height[st.top()], height[st.top()] + 1), inv), width[st.top()]));
add(sum, mul(mul(mul(height[i], height[i] + 1), inv), width[st.top()]));
can.push_back(st.top());
st.pop();
}
st.push(i);
add(res, mul(sum, width[i]));
add(res, mul(mul(mul(width[i], width[i] + 1), inv), mul(mul(height[i], height[i] + 1), inv)));
add(sum, mul(mul(mul(height[i], height[i] + 1), inv), width[i]));
for(int id: can) add(width[i], width[id]);
}
cout << res << '\n';
cerr << res << '\n';
}
bool M2;
signed main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define task "test"
if (fopen(task".inp", "r")){
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
input();
solve();
cerr << (1.0 * clock()) / CLOCKS_PER_SEC << ".s\n";
cerr << (&M2 - &M1) / 1048576 << " mb\n";
}
