#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<ctime>
#include<cctype>
#include<climits>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<memory>
#include<functional>
 
using namespace std;
 
#define ALL(g) (g).begin(),(g).end()
#define REP(i, x, n) for(int i = x; i < n; i++)
#define rep(i,n) REP(i,0,n)
#define F(i,j,k) fill(i[0],i[0]+j*j,k)
#define P(p) cout<<(p)<<endl;
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define INF 1<<25
#define pb push_back
 
typedef vector<int> vi;
typedef vector<long long> vl;
typedef vector<double> vd;
typedef pair<int,int> pii;
typedef pair<long,long> pll;
typedef long long ll;

int main(){
	int n;
	cin>>n;
	vector<ll> a(n);
	for(int i=0;i<n;i++)
		cin>>a[i];
	ll a_max=a[0],a_min=a[0]; //最大、最小を記録して動的計画法
	for(int i=1;i<n;i++){
		vector<ll> now;
		now.push_back(a[i]*a_max);
		now.push_back(a[i]*a_min);
		now.push_back(a[i]+a_max);
		now.push_back(a[i]+a_min);
		now.push_back(a_max-a[i]);
		now.push_back(a_min-a[i]);
		if(a[i]!=0){
			now.push_back(a_max/a[i]);
			now.push_back(a_min/a[i]);
		}
		sort(now.begin(),now.end());
		a_min=min(a_min,now[0]);
		ll last=now.back();
		a_max=max(a_max,last);
	}
	cout<<a_max<<endl;
	return 0;
}