#include <bits/stdc++.h>
using namespace std;
long long M[20],m[20];

int main(){
  int N;
  cin >> N;
  vector<long long> a(20);
  for(int i=0;i<N;i++)cin >> a[i];
  M[0]=a[0]; m[0]=a[0];
  for(int i=1;i<N;i++){
    if(a[i]==0){M[i]=M[i-1]; m[i]=m[i-1];}
    else if(a[i]>0){
      M[i]=max(M[i-1]+a[i],M[i-1]*a[i]);
      m[i]=min(m[i-1]-a[i],m[i-1]*a[i]);
    }
    else{
      M[i]=max(M[i-1]-a[i],m[i-1]*a[i]);
      m[i]=min(M[i-1]*a[i],m[i-1]+a[i]);
    }
  }
  cout << M[N-1] << endl;
}