heiban

#include <iostream>
#include <iomanip>
using namespace std;

int main() {
	int n;
	double sum = 1;
	double result = 1;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> sum;
		result *= sum;
	}
	cout << fixed << setprecision(2);
	cout << result;

	return 0;
}