#include "iostream"
#include "climits"
#include "list"
#include "queue"
#include "stack"
#include "set"
#include "functional"
#include "algorithm"
#include "math.h"
#include "utility"
#include "string"
#include "map"
#include "unordered_map"
#include "iomanip"
#include "random"

using namespace std;
const long long int MOD = 1000000007;

int N;
int num[16];
long long int ans = LLONG_MIN;

void Search(int n, long long int box,int end) {
	if (n == end) {
		ans = max(ans, box);
		return;
	}
	Search(n + 1, box + num[n + 1], end);
	Search(n + 1, box - num[n + 1], end);
	Search(n + 1, box * num[n + 1], end);
	if(num[n+1])Search(n + 1, box + num[n + 1], end);
}

int main() {
	cin >> N;
	for (int i = 0; i < N; i++)cin >> num[i];
	Search(0, num[0], N - 1);
	cout << ans << endl;
	return 0;
}