#include <bits/stdc++.h>
#include <atcoder/modint>
using namespace std;
using mint = atcoder::modint1000000007;
using ll = long long;

bool compare_Q(tuple<ll,ll,ll> A, tuple<ll,ll,ll> B){
    return {get<0>(A) * get<1>(B) < get<1>(A) * get<0>(B)};
}

int main(){
    ll N; cin >> N;
    vector<ll> A(N),B(N);
    for(ll i = 0; i < N; i++) cin >> A[i];
    for(ll i = 0; i < N; i++) cin >> B[i];

    ll cnt = 0;
    vector<tuple<ll,ll,ll>> C;
    for(ll i = 0; i < N; i++){
        if(A[i] == 0) continue;
        if(A[i] <= -1){A[i] *= -1; B[i] *= -1;}
        cnt += A[i];
        C.push_back({B[i], A[i], A[i]});
    }
    sort(C.begin(),C.end(),compare_Q);

    ll sum = 0, idx = 0;
    mint answer = 0;
    while(sum <= (cnt - 1) / 2){
        sum += get<2>(C[idx]);
        answer = get<0>(C[idx]);
        answer /= get<1>(C[idx]);
        idx++;
    }
    cout << answer.val() << "\n";
}