#include <bits/stdc++.h>

using namespace std;

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()

template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }

typedef unsigned long long ull;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<int, pii> P;

const ll INF = 1ll<<60;
const ll MOD = 1000000007;
const double EPS  = 1e-10;

int n;
int a[16];

int main() {
	cin >> n;
	REP(i, n) scanf("%d", a + i);
	
	ll ans = -INF;
	
	REP(s, 1 << n) {
		ll now = a[0];
		
		FOR(i, 1, n) {
			if (a[i] == 0) continue;
			
			if (s >> i & 1) now -= a[i];
			else {
				if (a[i] == 1) now++;
				else {
					if (now == 0) now += a[i];
					else now *= a[i];
				}
			}
		}
		
		chmax(ans, now);
	}
	
	cout << ans << endl;
	
	return 0;
}