#include "bits/stdc++.h"
using namespace std;
#define int long long
#define FOR(i, a, b) for(int i=(a);i<(b);i++)
#define RFOR(i, a, b) for(int i=(b-1);i>=(a);i--)
#define REP(i, n) for(int i=0; i<(n); i++)
#define RREP(i, n) for(int i=(n-1); i>=0; i--)
#define ALL(a) (a).begin(),(a).end()
#define UNIQUE_SORT(l) sort(ALL(l)); l.erase(unique(ALL(l)), l.end());
#define CONTAIN(a, b) find(ALL(a), (b)) != (a).end()
#define array2(type, x, y) array<array<type, y>, x>
#define vector2(type) vector<vector<type> >
#define out(...) printf(__VA_ARGS__)

int dxy[] = {0, 1, 0, -1, 0};

/*================================*/

int N,M,L;

signed main()
{
#if DEBUG
    std::ifstream in("input.txt");
    std::cin.rdbuf(in.rdbuf());
#endif
    cin>>N;
    int A[N];
    REP(i,N) cin>>A[i];
    int DP[2][2];
    DP[0][0] = DP[0][1] = A[0];
    FOR(i,1,N) {
        int ma = -LONG_LONG_MAX;
        int mi = LONG_LONG_MAX;
        int a = A[i];
        REP(k, 2) {
            ma = max(ma, DP[i-1][k]+a);
            ma = max(ma, DP[i-1][k]-a);
            ma = max(ma, DP[i-1][k]*a);
            mi = min(mi, DP[i-1][k]+a);
            mi = min(mi, DP[i-1][k]-a);
            mi = min(mi, DP[i-1][k]*a);
            if(a!=0) {
                ma = max(ma, DP[i-1][k]/a);
                mi = min(mi, DP[i-1][k]/a);
            }
        }
        DP[i][0]=ma;
        DP[i][1]=mi;
    }
    
     cout << DP[N-1][0] << endl;
    
    return 0;
}