// oooo
/*
har chi delet mikhad bebar ~
gitar o ba khodet nabar! ~
;Amoo_Hasan;
*/
#include<bits/stdc++.h>
//#pragma GCC optimize("O3,no-stack-protector,unroll-loops")
//#pragma GCC target("avx2,fma")
using namespace std;
typedef long long ll;
typedef long double ld;
#define Sz(x) int((x).size())
#define All(x) (x).begin(), (x).end()
#define wtf(x) cout<<#x <<" : " <<x <<endl
constexpr ll inf = 1e18, N = 1e5 + 10, mod = 1e9 + 7, pr = 1000696969;
int w[N], h[N];
int l[N], r[N];
ll ps[N], bpow;
ll poww(ll x, int y) {
ll res = 1;
for(; y; y /= 2, x = x * x % mod)
if(y & 1) {
res *= x;
res %= mod;
}
return res;
}
ll choose(ll x) {
ll ans = (x * (x - 1)) % mod;
ans *= bpow;
ans %= mod;
return ans;
}
int main() {
ios :: sync_with_stdio(0), cin.tie(0);
bpow = poww(2, mod - 2);
int n; cin >>n;
for(int i = 0; i < n; i++) cin >>h[i];
for(int i = 0; i < n; i++) cin >>w[i];
vector<int> vc;
for(int i = 0; i < n; i++) {
while(!vc.empty() && h[vc.back()] >= h[i]) vc.pop_back();
if(vc.empty()) l[i] = 0;
else l[i] = vc.back() + 1;
vc.push_back(i);
}
vc.clear();
for(int i = n - 1; i >= 0; i--) {
while(!vc.empty() && h[vc.back()] > h[i]) vc.pop_back();
if(vc.empty()) r[i] = n - 1;
else r[i] = vc.back() - 1;
vc.push_back(i);
}
for(int i = 0; i < n; i++) {
ps[i] = w[i];
if(i > 0) ps[i] += ps[i - 1];
ps[i] %= mod;
}
ll ans = 0;
for(int i = 0; i < n; i++) {
int mx = 0;
if(l[i] > 0) mx = max(mx, h[l[i] - 1] + 1);
if(r[i] < n - 1) mx = max(mx, h[r[i] + 1] + 1);
ll cnt = (choose(h[i] + 1) - choose(mx) + mod) % mod;
ll num = ps[r[i]];
if(l[i] > 0) num -= ps[l[i - 1]];
if(num < 0) num += mod;
num = choose(num + 1);
cnt *= num, cnt %= mod;
ans += cnt, ans %= mod;
}
cout<<ans;
return 0;
}
