#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<ll, ll>
#define fi first
#define sec second
#define ld long double
#pragma GCC optimize ("Ofast")
#pragma GCC optimize ("unroll-loops")
const int MAXN = 1e5;
const ll INF = 1e18;
const int MOD = 1e9 + 7;
ll res = 0;
ll H[MAXN + 5], W[MAXN + 5];
ll expo(ll a, ll b){
ll ans = 1;
while(b > 0){
if(b & 1) ans = ans * a % MOD;
a = a * a % MOD;
b /= 2;
}
return ans;
}
ll inv = expo(2, MOD - 2);
struct DSU{
ll N;
vector<ll> par, val;
DSU(ll _n){
N = _n;
par.resize(N + 5), val.resize(N + 5);
for(int i = 1; i <= N; i++) par[i] = i, val[i] = -1;
}
ll find(ll idx){
return (par[idx] == idx ? idx : par[idx] = find(par[idx]));
}
void join(ll a, ll b){
a = find(a), b = find(b);
if(a == b) return;
res = (res - (val[a] * (val[a] + 1) % MOD * inv % MOD) + MOD) % MOD;
res = (res - (val[b] * (val[b] + 1) % MOD * inv % MOD) + MOD) % MOD;
val[a] += val[b];
val[a] %= MOD;
res += val[a] * (val[a] + 1) % MOD * inv % MOD;
res %= MOD;
par[b] = a;
}
};
int main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int tc = 1;
// cin >> tc;
for(;tc--;){
ll N; cin >> N;
vector<pii> v;
for(int i = 1; i <= N; i++){
cin >> H[i];
}
for(int i = 1; i <= N; i++){
cin >> W[i];
v.push_back({H[i], i});
}
sort(v.begin(), v.end());
DSU dsu(N);
ll ans = 0;
while(true){
ll cur = v.back().fi;
while(!v.empty() && v.back().fi == cur){
res += W[v.back().sec] * (W[v.back().sec] + 1) % MOD * inv % MOD;
res %= MOD;
dsu.val[v.back().sec] = W[v.back().sec];
if(v.back().sec > 1 && dsu.val[dsu.find(v.back().sec - 1)] != -1){
dsu.join(v.back().sec, v.back().sec - 1);
}
if(v.back().sec < N && dsu.val[dsu.find(v.back().sec + 1)] != -1){
dsu.join(v.back().sec, v.back().sec + 1);
}
v.pop_back();
}
ll nxt;
if(!v.empty()) nxt = v.back().fi;
else nxt = 0;
ll Sn = (cur - nxt) * (2LL * cur - (cur - nxt - 1) + MOD) % MOD * inv % MOD;
ans += res * Sn % MOD;
ans %= MOD;
if(v.empty()) break;
}
cout << ans << "\n";
}
}
/*
*/
