/****ThanhCodeDao*****/
/*******Azazel*******/
#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define pb push_back
#define checkbit(mask,i) ((mask>>i)&1)
#define bit(i) (1<<i)
#define MLog 21
#define all(v) v.begin(), v.end()
#define uni(v) v.erase(unique(all(v)), v.end())
typedef long long ll;
const ll maxN = 1e5+3, modd = 1e9+7, nd2 = 500000004;
struct Point{
ll x,y;
};
ll cross(Point p,Point q,Point r){ // vi tri r voi duong pq >0 la ben trai, =0 la thang hang
ll val = (q.x-p.x)*(r.y-q.y) - (q.y-p.y)*(r.x-q.x);
if(val < 0) return -1;
if(val > 0) return 1;
return 0;
}
ll dot(Point vecA,Point vecB){ // tra ve >0 la nhon, <0 la tu, =0 la vuong, 2 vecto phai chung goc
ll val = vecA.x*vecB.x + vecA.y*vecB.y;
if(val < 0) return -1;
if(val > 0) return 1;
return 0;
}
double triarea(Point p,Point q,Point r){ // cross(pq * pr) / 2
double cross = (q.x-p.x)*(r.y-q.y) - (q.y-p.y)*(r.x-q.x);
return fabs(cross)/2.0;
}
/* de cho
*/
/* nhan xet nho
*/
/* nhan xet tu thuat trau
*/
int n;
int h[maxN], w[maxN];
ll ltnp(ll a,ll b){
if(b==0) return 1;
if(b==1) return a;
ll half = ltnp(a,b/2) % modd;
if(b%2){
return ((half*half)%modd * a)%modd;
}else{
return (half*half)%modd;
}
}
ll calc(ll sz){
return ((sz * (sz+1))%modd * nd2)%modd;
}
bool checksub4(){
for(int i = 2;i<=n;i++){
if(h[i] != h[i-1]) return false;
}
return true;
}
void sub4(){
ll sumw = 0;
for(int i = 1;i<=n;i++) sumw += w[i];
sumw %= modd;
cout << ((calc(h[1]) * calc(sumw))%modd);
}
bool checksub2(){
for(int i = 1;i<=n;i++){
if(h[i] == 1 or h[i] == 2) continue;
return false;
}
return true;
}
void sub2(){
ll ans = 0;
// h = 1
ll sumw = 0;
for(int i = 1;i<=n;i++) sumw += w[i];
sumw %= modd;
ans = calc(sumw);
// h2
for(int i = 1;i<=n;i++){
if(h[i] == 1) continue; // chi tinh h = 2
int j = i;
ll sumw = w[j];
while(j+1<=n and h[i] == h[j+1]){
sumw += w[j+1];
j++;
}
sumw %= modd;
ll res = (calc(h[i]) * calc(sumw))%modd;
res = (res - calc(sumw) + modd)%modd;
(ans += res)%=modd;
i = j;
}
cout << ans;
}
bool checksub1(){
if(n>50) return false;
for(int i = 1;i<=n;i++){
if(h[i] > 50) return false;
if(w[i] > 50) return false;
}
return true;
}
int sum[100][100];
int getsum(int stx,int sty,int fnx,int fny){
return sum[fnx][fny] - sum[fnx][sty-1] - sum[stx-1][fny] + sum[stx-1][sty-1];
}
void sub1(){
int mxw = 0;
int mxh = 0;
int ans = 0;
for(int i = 1;i<=n;i++){
for(int z = 1;z<=w[i];z++){
++mxw;
for(int j = 1;j<=h[i];j++){
sum[j][mxw] = 1;
}
}
mxh = max(mxh,h[i]);
}
for(int i = 1;i<=mxh;i++){
for(int j = 1;j<=mxw;j++){
sum[i][j] = sum[i-1][j] + sum[i][j-1] - sum[i-1][j-1] + sum[i][j];
}
}
for(int dai = 1;dai<=mxh;dai++){
for(int rong = 1;rong<=mxw;rong++){
for(int i = 1;i<=mxh;i++){
for(int j = 1;j<=mxw;j++){
int nxti = i + dai - 1, nxtj = j + rong - 1;
if(nxti <= mxh and nxtj <= mxw and getsum(i,j,nxti,nxtj) == (dai*rong)){
++ans;
}
}
}
}
}
cout << ans;
}
bool checksub5(){
for(int i = 1;i<=n-1;i++){
if(h[i] <= h[i+1]) continue;
return false;
}
return true;
}
void sub5(){
ll sumw = 0;
for(int i = 1;i<=n;i++){
(sumw += w[i])%=modd;
}
ll ans = 0;
ll preh = 0;
for(int i = 1;i<=n;i++){
// cout << sumw << '\n';
ll cur = (calc(h[i]) * (calc(sumw)))%modd;
(ans += cur)%=modd;
ans = (ans - (calc(preh)*calc(sumw))%modd + modd)%modd;
(ans += modd)%=modd;
preh = h[i];
int j = i;
(sumw = sumw - w[j] + modd)%=modd;
while(j+1<=n and h[j+1] == h[i]){
(sumw = sumw - w[j+1] + modd)%=modd;
++j;
}
i = j;
}
cout << ans;
}
void solve() {
cin >> n;
for(int i = 1;i<=n;i++) cin >> h[i];
for(int i = 1;i<=n;i++) cin >> w[i];
if(checksub5()){
sub5();
return;
}
if(checksub4()){
sub4();
return;
}
if(checksub2()){
sub2();
return;
}
if(checksub1()){
sub1();
return;
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0), cout.tie(0);
// freopen("inp.txt","r",stdin);
//freopen("out.txt","w",stdout);
solve();
return 0;
}
