#include <iostream>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <cstdio>
#include <cstring>
#include <math.h>
using namespace std;
typedef long long ll;
typedef double D;
typedef pair<int,int> P;
#define M 1000000007
#define F first
#define S second
#define PB push_back
ll n,ma,mi;
int main(void){
    cin>>n>>ma;
    mi=ma;
    for(int i=1;i<n;i++){
        ll a;
        cin>>a;
        ll x=ma,y=mi;
        ma=max(max(max(x+a,x-a),x*a),max(max(y+a,y-a),y*a));
        mi=min(min(min(x+a,x-a),x*a),min(min(y+a,y-a),y*a));
        if(a){
            ma=max(ma,max(x/a,y/a));
            mi=min(mi,min(x/a,y/a));
        }
    }
    cout<<ma<<endl;
}