text: // Tags: Math
  // Difficulty: 2.0
  // Priority: 5
  // Date: 17-08-2020
  
  #include <bits/stdc++.h>
       
  #define all(A) begin(A), end(A)
  #define rall(A) rbegin(A), rend(A)
  #define sz(A) int(A.size())
  #define pb push_back
  #define mp make_pair
       
  using namespace std;
       
  typedef long long ll;
  typedef pair <int, int> pii;
  typedef pair <ll, ll> pll;
  typedef vector <int> vi;
  typedef vector <ll> vll;
  typedef vector <pii> vpii;
  typedef vector <pll> vpll;
  
  int main () {
    ios::sync_with_stdio(false); cin.tie(0);
    int n;
    cin >> n;
    vi x(n);
    for (int& xi: x) cin >> xi;
    int m;
    cin >> m;
    vi y(m);
    for (int& yi: y) cin >> yi;
    int k;
    cin >> k;
    vi z(k);
    for (int& zi: z) cin >> zi;
    int A, B;
    cin >> A >> B;
    double r2 = 0;
    int r1 = *max_element(all(x));
    for (int p1: y) {
      for (int p2: z) {
        double r2_t = r1 * sqrt(1.0 * (p1 * B) / (p1 * B + p2 * A));
        if (r2_t < r1) r2 = max(r2, r2_t);
      }
    }
    cout << fixed << setprecision(12) << r2 << '\n';
    return (0);
  }
  