#include <bits/stdc++.h>

using namespace std;

typedef long long int64;
const int64 INF = 1LL << 58;


int N, A[16];

int64 createArray(int idx, int sz, int64 val)
{
  if(idx == sz) return (val);
  int64 ret = -INF;
  ret = max(ret, createArray(idx + 1, sz, val + A[idx]));
  ret = max(ret, createArray(idx + 1, sz, val - A[idx]));
  ret = max(ret, createArray(idx + 1, sz, val * A[idx]));
  return (ret);
}

int main()
{
  cin >> N;
  for(int i = 0; i < N; i++) {
    cin >> A[i];
  }
  cout << createArray(1, N, A[0]) << endl;
}