#include <bits/stdc++.h>
using namespace std;
mt19937 mt(chrono::steady_clock::now().time_since_epoch().count()); // teste
#define int long long
#define fi first
#define se second
#define pb push_back
// #define endl '\n'
typedef long long ll;
typedef pair<int,int> pii;
const int N = 1e5+5;
const int mod = 1e9+7;
const int inv2 = (mod+1)/2;
const int INF = 1e9+5;
int a[N], b[N];
int accu[N];
int pai[N], lef[N], rig[N];
int Calc(int x, int y)
{
int ans = 1;
ans = (ans*x)%mod;
ans = (ans*(x+1))%mod;
ans = (ans*inv2)%mod;
ans = (ans*y)%mod;
ans = (ans*(y+1))%mod;
ans = (ans*inv2)%mod;
return ans;
}
int Solv(int u, int l, int r)
{
int ans = 0;
if(!pai[u] || a[pai[u]]!=a[u])
{
int x = accu[r]-accu[l-1];
ans = (Calc(a[u], x)+mod-Calc(a[pai[u]], x))%mod;
}
if(lef[u]) ans = (ans+Solv(lef[u], l, u-1))%mod;
if(rig[u]) ans = (ans+Solv(rig[u], u+1, r))%mod;
return ans;
}
int32_t main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n;
cin >> n;
for(int i = 1;i <= n;i++) cin >> a[i];
for(int i = 1;i <= n;i++) cin >> b[i];
for(int i = 1;i <= n;i++) accu[i] = accu[i-1]+b[i];
stack<int> pilha;
for(int i = 1;i <= n;i++) pai[i] = lef[i] = rig[i] = 0;
for(int i = 1;i <= n;i++)
{
int ult = 0;
while(!pilha.empty() && a[pilha.top()]>a[i])
{
ult = pilha.top();
pilha.pop();
}
if(ult)
{
pai[ult] = i;
lef[i] = ult;
}
if(!pilha.empty())
{
pai[i] = pilha.top();
rig[pilha.top()] = i;
}
pilha.push(i);
}
int root = 1;
while(pai[root]) root++;
cout << Solv(root, 1, n) << endl;
return 0;
}
