#include <bits/stdc++.h>
using namespace std;
char ord[101];
int n1, n2, n3, a[6000], b[6000], c[6000];
double ans, A, B;
int main() {
  scanf("%d", &n1);
  for (int i = 1; i <= n1; i++) scanf("%d", &a[i]);
  scanf("%d", &n2);
  for (int i = 1; i <= n2; i++) scanf("%d", &b[i]);
  scanf("%d", &n3);
  for (int i = 1; i <= n3; i++) scanf("%d", &c[i]);
  cin >> A >> B;
  sort(a + 1, a + 1 + n1);
  sort(b + 1, b + 1 + n2);
  ans = 0;
  sort(c + 1, c + 1 + n3);
  for (int i = 1; i <= n1; i++)
    for (int j = 1; j <= n2; j++) {
      double p1 = (double)b[j], r1 = (double)a[i], r2, p2 = (double)c[1];
      r2 = sqrt(p1 * r1 * r1 * B / (A * p2 + B * p1));
      ans = max(r2, ans);
    }
  printf("%.8lf", ans);
}
