#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define fi first
#define se second
#define pll pair<ll,ll>
#define pb push_back
#define debug(x) cerr<<#x<<"="<<x<<endl;
#define MP make_pair
#define rep(i,a,b) for(ll i=a;i<b;i++)
#define SZ(x) (ll)x.size()
#define ALL(x) x.begin(),x.end()
#define endl "\n"
const ll inf=1e18;
ll lowbit(ll x){return x&(-x);}
const ll mod=1e9+7;
ll c2(ll x){
return (x*(x-1)/2)%mod;
}
ll rect(ll x,ll y){
ll xx=(x*(x+1)/2)%mod;
ll yy=(y*(y+1)/2)%mod;
return (xx*yy)%mod;
}
const ll maxn=1e5+5;
ll h[maxn],w[maxn],pre[maxn];
ll inc(ll &a,ll b){return a=(a+b)%mod;}
ll dec(ll &a,ll b){return a=(a-b+mod)%mod;}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
ll n;cin>>n;
ll tot=0,ans=0;
rep(i,1,n+1)cin>>h[i];
rep(i,1,n+1){
cin>>w[i],inc(tot,w[i]);
pre[i]=pre[i-1]+w[i];
}
stack<pll>s;
//monotonically increasing stack
s.push(MP(0ll,0ll));
rep(i,1,n+1){
while(!s.empty() and s.top().se>h[i])s.pop();
ll len=(pre[i-1]-pre[s.top().se]+mod)%mod;
inc(ans,(((c2(h[i]+1)*len)%mod)*w[i])%mod);
inc(ans,(s.top().se*w[i])%mod);
inc(ans,rect(h[i],w[i]));
s.push(MP(i,(c2(h[i]+1)*(w[i]))%mod));
}
cout<<ans<<endl;
return 0;
}
