#include<bits/stdc++.h>
using namespace std;

#define int long long

#define rep(i,n) for(int i=0;i<(n);i++)
#define pb push_back
#define all(v) (v).begin(),(v).end()
#define fi first
#define se second
typedef vector<int>vint;
typedef pair<int,int>pint;
typedef vector<pint>vpint;

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

int N;
int A[22];

int ma[22],mi[22];

signed main(){
    cin>>N;
    rep(i,N)cin>>A[i];

    fill_n(ma,22,LLONG_MIN);
    fill_n(mi,22,LLONG_MAX);

    ma[1]=A[0];
    mi[1]=A[0];

    for(int i=1;i<N;i++){
        chmax(ma[i+1],ma[i]+A[i]);
        chmax(ma[i+1],ma[i]-A[i]);
        chmax(ma[i+1],ma[i]*A[i]);
        if(A[i])chmax(ma[i+1],ma[i]/A[i]);

        chmax(ma[i+1],mi[i]+A[i]);
        chmax(ma[i+1],mi[i]-A[i]);
        chmax(ma[i+1],mi[i]*A[i]);
        if(A[i])chmax(ma[i+1],mi[i]/A[i]);


        chmin(mi[i+1],ma[i]+A[i]);
        chmin(mi[i+1],ma[i]-A[i]);
        chmin(mi[i+1],ma[i]*A[i]);
        if(A[i])chmin(mi[i+1],ma[i]/A[i]);

        chmin(mi[i+1],mi[i]+A[i]);
        chmin(mi[i+1],mi[i]-A[i]);
        chmin(mi[i+1],mi[i]*A[i]);
        if(A[i])chmin(mi[i+1],mi[i]/A[i]);
    }

    cout<<ma[N]<<endl;
    return 0;
}