#line 1 "combined.cpp"

#include <algorithm>
#include <cassert>
#include <vector>

namespace atcoder {

struct dsu {
  public:
    dsu() : _n(0) {}
    dsu(int n) : _n(n), parent_or_size(n, -1) {}

    int merge(int a, int b) {
        assert(0 <= a && a < _n);
        assert(0 <= b && b < _n);
        int x = leader(a), y = leader(b);
        if (x == y) return x;
        if (-parent_or_size[x] < -parent_or_size[y]) std::swap(x, y);
        parent_or_size[x] += parent_or_size[y];
        parent_or_size[y] = x;
        return x;
    }

    bool same(int a, int b) {
        assert(0 <= a && a < _n);
        assert(0 <= b && b < _n);
        return leader(a) == leader(b);
    }

    int leader(int a) {
        assert(0 <= a && a < _n);
        if (parent_or_size[a] < 0) return a;
        return parent_or_size[a] = leader(parent_or_size[a]);
    }

    int size(int a) {
        assert(0 <= a && a < _n);
        return -parent_or_size[leader(a)];
    }

    std::vector<std::vector<int>> groups() {
        std::vector<int> leader_buf(_n), group_size(_n);
        for (int i = 0; i < _n; i++) {
            leader_buf[i] = leader(i);
            group_size[leader_buf[i]]++;
        }
        std::vector<std::vector<int>> result(_n);
        for (int i = 0; i < _n; i++) {
            result[i].reserve(group_size[i]);
        }
        for (int i = 0; i < _n; i++) {
            result[leader_buf[i]].push_back(i);
        }
        result.erase(
            std::remove_if(result.begin(), result.end(),
                           [&](const std::vector<int>& v) { return v.empty(); }),
            result.end());
        return result;
    }

  private:
    int _n;
    std::vector<int> parent_or_size;
};

}  // namespace atcoder

#include <iostream>
#include <iomanip>
#line 71 "combined.cpp"

using namespace std;
using lint = long long;
using ldouble = long double;

void solve() {
    int n;
    cin >> n;

    vector<lint> ds(n);
    for (auto& d : ds) cin >> d;
    for (auto& d : ds) {
        int b;
        cin >> b;
        d -= b;
    }

    vector<ldouble> ps(n, 0);
    vector<bool> zero(n, false);
    for (int i = 0; i < n; ++i) {
        int p;
        cin >> p;

        if (p == 0) {
            zero[i] = true;
        } else {
            ps[i] = 1.L / p;
        }
    }

    auto cost = [&](int v) {
        return zero[v] ? 0 : ds[v] * ds[v] / ps[v];
    };

    ldouble ans = 0;
    for (int v = 0; v < n; ++v) ans += cost(v);

    atcoder::dsu dsu(n);
    int q;
    cin >> q;
    while (q--) {
        int u, v;
        cin >> u >> v;
        --u, --v;

        u = dsu.leader(u);
        v = dsu.leader(v);

        if (u != v) {
            ans -= cost(u);
            ans -= cost(v);

            auto nd = ds[u] + ds[v];
            auto np = ps[u] + ps[v];
            auto nz = zero[u] || zero[v];

            auto w = dsu.merge(u, v);
            ds[w] = nd, ps[w] = np, zero[w] = nz;
            ans += cost(w);
        }

        cout << ans << "\n";
    }
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);

    solve();

    return 0;
}