#include<bits/stdc++.h>
#define fo(i,d,c) for(int i=d;i<=c;i++)
#define fod(i,c,d) for(int i=c;i>=d;i--)
#define maxn 1000010
#define N 1010
#define fi first
#define se second
#define pb emplace_back
#define en cout<<"\n";
#define int long long
#define inf 1000000000
#define pii pair<int,int>
#define vii vector<pii>
#define lb(x) x&-x
#define bit(i,j) ((i>>j)&1)
#define offbit(i,j) (i^(1<<j))
#define onbit(i,j) (i|(1<<j))
#define vi vector<int>
template <typename T1, typename T2> bool minimize(T1 &a, T2 b)
{
if (a > b)
{
a = b;
return true;
}
return false;
}
template <typename T1, typename T2> bool maximize(T1 &a, T2 b)
{
if (a < b)
{
a = b;
return true;
}
return false;
}
using namespace std;
const int mod = 1e9 + 7;
int n;
int h[maxn],w[maxn];
int inv[maxn];
int Pow(int a,int n)
{
int ans = 1;
for( ; n ; n >>= 1, a = ((a * a) % mod + mod) % mod) if(n & 1)
{
ans = ((ans * a) % mod + mod) % mod;
}
return ans;
}
int C(int n)
{
return n % mod * (n - 1) % mod * inv[2] % mod ;
}
int T(int a,int b)
{
return C(a + 1) * C(b + 1) % mod;
}
int ans;
int done[maxn];
struct DSU
{
vi par,sz;
DSU(int n) : par(n),sz(n) {};
void make(int u)
{
par[u] = u;
sz[u] = 1;
}
int find(int u)
{
return u == par[u] ? u : par[u] = find(par[u]);
}
void Union(int u,int v,int h)
{
u = find(u);
v = find(v);
if(u == v) return ;
ans = (ans + T(h,w[u] + w[v]) - T(h,w[u]) - T(h,w[v])) % mod;
ans = (ans + mod) % mod;
if(sz[u] < sz[v]) swap(u,v);
sz[u] += sz[v];
par[v] = u;
w[u] = (w[u] + w[v]) % mod;
}
};
main()
{
#define name "TASK"
if(fopen(name".inp","r"))
{
freopen(name".inp","r",stdin);
freopen(name".out","w",stdout);
}
ios_base::sync_with_stdio(false);
cin.tie(NULL);
inv[2] = Pow(2,mod - 2);
cin >> n;
fo(i,1,n) cin >> h[i];
fo(i,1,n) cin >> w[i];
DSU g(n + 5);
fo(i,1,n) g.make(i);
fo(i,1,n) ans = (ans + T(w[i],h[i])) % mod;
vi v;
fo(i,1,n) v.pb(i);
sort(v.begin(),v.end(),[](int a,int b)
{
return h[a] > h[b];
});
for(int i : v)
{
if(h[i] <= h[i + 1] and done[i + 1])
{
g.Union(i,i + 1,h[i]);
}
if(h[i] <= h[i - 1] and done[i - 1])
{
g.Union(i,i - 1,h[i]);
}
done[i] = 1;
}
cout << ans;
}
