#include<bits/stdc++.h>
using namespace std;
#define mod 1000000007
typedef long long ll;
typedef pair<ll,ll> pii;
ll count_rect(pii a){
return ((a.first+1)*(a.first)/2%mod)*((a.second+1)*(a.second)/2%mod)%mod;
}
pii merge(ll& result, pii& a, pii b){
if (a.first >= b.first){
result += count_rect(a) - count_rect({b.first, a.second});
result %= mod;
return {b.first, (a.second+b.second)%mod};
} else {
result += count_rect(b) - count_rect({a.first, b.second});
result %= mod;
return {a.first, (a.second+b.second)%mod};
}
}
int main(){
int n; cin >> n;
vector<ll> vysky(n+1, 0);
vector<ll> sirky(n+1, 0);
for (int i = 0 ;i<n; i++) cin >> vysky[i];
for (int i = 0; i<n; i++) cin >> sirky[i];
vector<pii> stc;
stc.push_back({-1,-1});
stc.push_back({vysky[0], sirky[0]});
ll result = 0;
for (int i = 1; i<n+1; i++){
if (vysky[i] > stc.back().first){
stc.push_back({vysky[i],sirky[i]});
} else {
while (stc[stc.size()-2].first >= vysky[i]){
pii novy = merge(result, stc[stc.size()-2], stc[stc.size()-1]);
stc.pop_back(); stc.pop_back();
stc.push_back(novy);
}
if (vysky[i] > stc.back().first){
stc.push_back({vysky[i], sirky[i]});
} else {
pii novy = merge(result, stc.back(), {vysky[i], sirky[i]});
stc.pop_back();
stc.push_back(novy);
}
}
}
cout << (result+mod)%mod << endl;
}
