#include <bits/stdc++.h>
using namespace std;
double a[5005], b[5005], c[5005];
int cmp(double a, double b) { return a > b; }
int cmp2(double a, double b) { return a < b; }
int main() {
  int n;
  double A, B;
  while (scanf("%d", &n) != EOF) {
    for (int i = 0; i < n; i++) scanf("%lf", &a[i]);
    sort(a, a + n, cmp);
    scanf("%d", &n);
    for (int i = 0; i < n; i++) scanf("%lf", &b[i]);
    sort(b, b + n, cmp);
    scanf("%d", &n);
    for (int i = 0; i < n; i++) scanf("%lf", &c[i]);
    sort(c, c + n, cmp2);
    scanf("%lf %lf", &A, &B);
    printf("%.12lf\n", sqrt(B * a[0] * a[0] * b[0] / (A * c[0] + B * b[0])));
  }
  return 0;
}
