#include<bits/stdc++.h>
using namespace std;
#define int long long
#define all(x) x.begin(),x.end()
const long long inf=1e18;
const int mod=1e9+7;
void solve(){
int n;
cin>>n;
vector<int>a(n),b(n);
for(int i=0;i<n;i++){
cin>>a[i];
}
for(int i=0;i<n;i++){
cin>>b[i];
}
int ans=0;
deque<pair<int,int>>q;
for(int i=0;i<n;i++){
for(int j=a[i];j<=b[i];j++){
q.push_back({j,i});
}
}
while(!q.empty()){
auto [x,ind]=q.front();
q.pop_front();
ans++;
ans%=mod;
for(int j=ind+1;j<n;++j){
if(b[j]>x){
for(int k=max(a[j],x+1);k<=b[j];++k){
q.push_front({k,j});
}
break;
}
}
}
cout<<ans<<'\n';
}
signed main(){
int t=1;
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
//cin>>t;
while(t--){
solve();
}
}
