#include<bits/stdc++.h>
using namespace std;
const long long inf = (long long) 1e18 + 10;
const int inf1 = (int) 1e9 + 10;
#define int long long
#define dbl long double
#define endl '\n'
#define sc second
#define fr first
#define mp make_pair
#define pb push_back
#define all(x) x.begin(), x.end()
const int maxn = 1e5+10;
const int mod = 1e9+7;
int n, h[maxn], w[maxn], ps[maxn];
map<int,vector<int>> ed;
int vz(int a, int b) {
return a*b%mod;
}
void solve() {
cin >> n;
for(int i = 1; i <= n; i++) {
cin >> h[i];
ed[h[i]].pb(i);
}
for(int i = 1; i <= n; i++) {
cin >> w[i];
ps[i] = ps[i-1]+w[i]; ps[i]%= mod;
}
set<pair<int,int>> st;
st.insert(mp(1,n));
int curw = ps[n]*(ps[n]+1)/2; curw%= mod;
int ant = 0;
int ans = 0;
for(auto X : ed) {
int val = X.fr;
// l = ant+1 r = val
int aux = (val-ant)*(val+ant+1)/2;
aux%= mod;
curw%= mod;
ans+= (curw*aux)%mod; ans%= mod;
ant = val;
for(auto i : X.sc) {
auto it = st.upper_bound(mp(i,inf)); it--;
int l = it->fr;
int r = it->sc;
curw-= (ps[r]-ps[l-1])*(ps[r]-ps[l-1]+1)/2; curw%= mod;
st.erase(it);
if(i != l) {
st.insert(mp(l,i-1));
curw+= (ps[i-1]-ps[l-1])*(ps[i-1]-ps[l-1]+1)/2; curw%= mod;
}
if(i != r) {
st.insert(mp(i+1,r));
curw+= (ps[r]-ps[i])*(ps[r]-ps[i]+1)/2; curw%= mod;
}
}
}
ans = (ans+mod)%mod;
cout << ans << endl;
}
int32_t main() {
ios::sync_with_stdio(false); cin.tie(0);
// freopen("in.in", "r", stdin);
// freopen("out.out", "w", stdout);
int tt = 1;
// cin >> tt;
while(tt--) {
solve();
}
}
