#include <bits/stdc++.h>   using namespace std;   const int N = 6001;   int n, m, k, a, b, x[N], y[N], z[N];   int main() {     scanf( %d , &n);     for (int i = 1; i <= n; i++) scanf( %d , &x[i]);     scanf( %d , &m);     for (int i = 1; i <= m; i++) scanf( %d , &y[i]);     scanf( %d , &k);     for (int i = 1; i <= k; i++) scanf( %d , &z[i]);     scanf( %d%d , &a, &b);     sort(x + 1, x + 1 + n);     sort(y + 1, y + 1 + m);     sort(z + 1, z + 1 + k);     double p2 = z[1];     double r1 = x[n];     double res = 0;     for (int i = 1; i <= m; i++) {       double p1 = y[i];       double cur = (p1 * b * r1 * r1) / (p1 * b + p2 * a);       cur = sqrt(cur);       if (cur - res > 1e-6) res = cur;     }     printf( %.7f n , res);     return 0;   }   