#include <bits/stdc++.h>   using namespace std;   int main() {     int n, i, j, k;     double maxm, sum, r;     cin >> n;     double A[n];     for (i = 0; i < n; i++) cin >> A[i];     sort(A, A + n);     maxm = A[n - 1];     for (i = n - 1; i >= 0; i--) {       sum = 0;       for (j = n - 1; j >= i; j--) {         r = A[j];         for (k = n - 1; k >= i; k--) {           if (k != j) r = r * (double(1.0) - A[k]);         }         sum += r;       }       if (sum > maxm) maxm = sum;     }     cout << setprecision(10) << maxm << endl;   }   