#include <bits/extc++.h>
#include <atcoder/modint>

int main(){
    using namespace std;
    using modint = atcoder::static_modint<1000000007>;
    unsigned long N;
    cin >> N;
    vector<pair<unsigned long, unsigned long>> jobs(N);
    for(auto&& [a, _] : jobs)cin >> a;
    for(auto&& [_, b] : jobs)cin >> b;
    sort(begin(jobs), end(jobs), [](auto&& i, auto&& j){
        auto&& [a0, b0]{i};
        auto&& [a1, b1]{j};
        return a0 + a1 * b0 > a1 + a0 * b1;
    });
    modint ans{}, now_level{1};
    for(const auto& [a, b] : jobs){
        ans += now_level * a;
        now_level *= b;
    }
    cout << ans.val() << endl;
    return 0;
}