#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  int a[5005];
  while (scanf("%d", &n) != EOF) {
    for (int i = (0); i < (n); i++) scanf("%d", &a[i]);
    sort(a, a + n);
    double r1 = 1.0 * a[n - 1];
    scanf("%d", &n);
    for (int i = (0); i < (n); i++) scanf("%d", &a[i]);
    sort(a, a + n);
    double p1 = 1.0 * a[n - 1];
    scanf("%d", &n);
    for (int i = (0); i < (n); i++) scanf("%d", &a[i]);
    sort(a, a + n);
    double p2 = 1.0 * a[0];
    double A, B;
    scanf("%lf%lf", &A, &B);
    double r2 = sqrt(B * r1 * r1 * p1 / (B * p1 + p2 * A));
    printf("%.12lf\n", r2);
  }
}
