/*
_____________________.
|____________________| $$\ $$\ $$\ $$\
|____________________| $$ | \__| $$ | $$ |
|____________________| $$$$$$\ $$$$$$\ $$$$$$\ $$$$$$$\ $$$$$$$\ $$$$$$\ $$\ $$$$$$\ $$$$$$$\ $$$$$$\ $$$$$$$\
|____________________| \_$$ _| $$ __$$\ \____$$\ $$ __$$\ $$ _____| $$ __$$\ $$ |$$ __$$\ $$ __$$\\_$$ _| $$ _____|
|____________________| $$ | $$ | \__|$$$$$$$ |$$ | $$ |\$$$$$$\ $$ | \__|$$ |$$ / $$ |$$ | $$ | $$ | \$$$$$$\
$$ |$$\ $$ | $$ __$$ |$$ | $$ | \____$$\ $$ | $$ |$$ | $$ |$$ | $$ | $$ |$$\ \____$$\
\$$$$ |$$ | \$$$$$$$ |$$ | $$ |$$$$$$$ | $$ | $$ |\$$$$$$$ |$$ | $$ | \$$$$ |$$$$$$$ |
へ ♡ \____/ \__| \_______|\__| \__|\_______/ \__| \__| \____$$ |\__| \__| \____/ \_______/
૮ - ՛) $$\ $$ |
/ ⁻ ៸| \$$$$$$ | are human rights :3
乀 (ˍ,ل ل \______/
*/
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag,
tree_order_statistics_node_update>;
template <typename T>
using ordered_multiset = tree<pair<T, long long>, null_type,
less<pair<T, long long>>, rb_tree_tag,
tree_order_statistics_node_update>;
using namespace std;
using namespace __gnu_pbds;
#define ll long long
#define ull unsigned long long
#define ld long double
#define inf (ll)2e18+4
#define pb push_back
#define se second
#define fi first
#define endl '\n'
#define mp make_pair
#define pll pair<ll,ll>
#define kth_smallest find_by_order
#define num_of_smaller order_of_key
#define fori(x) for(ll i=0;i<x;i++)
#define forj(y) for(ll j=0;j<y;j++)
#define fork(z) for(ll k=0;k<z;k++)
#define forl(a) for(ll l=0;l<a;l++)
#define DEBUG
#ifdef DEBUG
#define show(x) cerr<<#x<<" is "<<x<<endl;
#define show2(x,y) cerr<<#x<<" is "<<x<<" "<<#y<<" is "<<y<<endl;
#define show3(x,y,z) cerr<<#x<<" is "<<x<<" "<<#y<<" is "<<y<<" "<<#z<<" is "<<z<<endl;
#define show4(x,y,z,a) cerr<<#x<<" is "<<x<<" "<<#y<<" is "<<y<<" "<<#z<<" is "<<z<<" "<<#a<<" is "<<a<<endl;
#define show_vec(a) for(auto &i:a)cerr<<i<<" ";cerr<<endl;
#define skillissue cerr<<"your code is running\n";
#define getchar_unlocked _getchar_nolock // comment before submission
#else
#define show(x)
#define show2(x,y)
#define show3(x,y,z)
#define show4(x,y,z,a)
#define show_vec(a)
#define skillissue
#endif
/*
inline int readint() {
int x=0; char ch=getchar_unlocked(); bool s=1;
while(ch<'0'||ch>'9'){if(ch=='-')s=0;ch=getchar_unlocked();}
while(ch>='0'&&ch<='9'){x=(x<<3)+(x<<1)+ch-'0';ch=getchar_unlocked();}
return s?x:-x;
}
*/
const ll mod=1e9+7;
ll summ(ll x,ll y){
return ((x+y)*(y-x+1)/2) % mod;
}
struct node{
ll S,E,val,lazyset,lazyadd,M;
node *l,*r;
node(ll s,ll e){
S=s;E=e;val=0,lazyset=-1,lazyadd=0;
M=(S+E)/2;
if(S==E)return;
l=nullptr;
r=nullptr;
}
void prop(){
if(S==E)return;
if(l==nullptr){
l=new node(S,M);
r=new node(M+1,E);
}
if(lazyset!=-1){
l->lazyset=lazyset;
l->val=(summ(l->S,l->E)*lazyset)%mod;
r->lazyset=lazyset;
r->val=(summ(r->S,r->E)*lazyset)%mod;
lazyset=-1;
lazyadd=0;
}else{
l->lazyadd=lazyadd;
l->val=(l->val+(summ(l->S,l->E)*lazyadd)%mod)%mod;
r->lazyadd=lazyadd;
r->val=(r->val+(summ(r->S,r->E)*lazyadd)%mod)%mod;
lazyadd=0;
}
}
ll qry(){
return val;
}
void set(ll x,ll y,ll v){
//show4(x,y,E,S)
if(x>E or y<S)return;
prop();
if(x<=S and E<=y){
val=summ(S,E)*v;
lazyset=v;
if(lazyadd!=0)lazyadd=0;
return;
}
prop();
l->set(x,y,v);
r->set(x,y,v);
val=(l->val+r->val)%mod;
}
void add(ll x,ll y,ll v){
//show4(x,y,E,S)
if(x>E or y<S)return;
prop();
if(x<=S and E<=y){
val=(val+summ(S,E)*v)%mod;
lazyadd+=v;
return;
}
prop();
l->add(x,y,v);
r->add(x,y,v);
val=(l->val+r->val)%mod;
}
};
int32_t main(){
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
ll n;cin>>n;
ll h[n],b[n];
fori(n)cin>>h[i];
fori(n)cin>>b[i];
node *root=new node(0,1e9+4);
ll ans=0;
fori(n){
root->set(h[i]+1,1e9+4,0);
ans = ((ans + root->qry())%mod + ((b[i]*(b[i]+1)/2)%mod * (h[i]*(h[i]+1)/2)%mod)%mod);
root->add(0,h[i],b[i]);
}
cout<<ans%mod;
}
