#define  _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <algorithm>
#include <utility>
#include <functional>
#include <cstring>
#include <queue>
#include <stack>
#include <math.h>
#include <iterator>
#include <vector>
#include <string>
#include <set>
#include <math.h>
#include <iostream> 
#include<map>
#include <iomanip>
#include <time.h>
#include <stdlib.h>
#include <list>
#include <typeinfo>
#include <list>
#include <set>
using namespace std;
#define LONG_INF 10000000000000000
#define MAX_MOD 1000000007
#define REP(i,n) for(long long i = 0;i < n;++i)
int main() {
	int n;
	cin >> n;
	vector<long long> a;
	REP(i, n) {
		long long hoge;
		cin >> hoge;
		a.push_back(hoge);
	}
	long long big_max = a[0];
	long long small_min = a[0];
	for (int i = 1;i < n;++i) {
		vector<long long> hogee;
		hogee.push_back(a[i] * big_max);
		hogee.push_back(a[i] * small_min);
		hogee.push_back(small_min + a[i]);
		hogee.push_back(big_max + a[i]);
		hogee.push_back(small_min - a[i]);
		hogee.push_back(big_max - a[i]);
		if (a[i] != 0) {
			hogee.push_back(big_max / a[i]);
			hogee.push_back(small_min / a[i]);
		}
		sort(hogee.begin(), hogee.end());
		small_min = min(small_min, hogee[0]);
		big_max = max(big_max, hogee[hogee.size() - 1]);
	}
	cout << big_max << endl;
	return 0;
}