#include <bits/stdc++.h>
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define fi first
#define se second

using std::cin;
using std::cout;
using std::vector;
using ll = long long;
using P = std::pair<ll, ll>;
using mint = modint1000000007;

int main() {
    int n;
    cin >> n;
    
    vector<P> p(n);
    rep(i, n) cin >> p[i].fi;
    rep(i, n) cin >> p[i].se;
    
    sort(p.begin(), p.end(), [&](P l, P r) {
        return r.fi*(l.se-1) > l.fi*(r.se-1);
    });
    
    mint ans, x = 1;
    for (auto [a, b] : p) {
        ans += x*a;
        x *= b;
    }
    
    cout << ans.val() << '\n';
    
    return 0;
}