#include <bits/stdc++.h>   using namespace std;   int main() {     int i, j, k, n;     cin >> n;     vector<long double> probs(n);     for (i = 0; i < n; i++) {       cin >> probs[i];     }     sort(probs.begin(), probs.end());     reverse(probs.begin(), probs.end());     long double prob0 = 1;     long double prob1 = 0.;     for (i = 0; i < n; i++) {       long double p = prob1;       p = probs[i] * prob0 + p * (1 - probs[i]);       if (p > prob1) {         prob1 = p;         prob0 = (1 - probs[i]) * prob0;       }     }     printf( %.9lf , double(prob1 + 0.0000000001));     return 0;   }   