import java.io.*;
import java.math.*;
import java.util.*;

public class Main {


    static BigInteger ans, a2, a3;
    static int dans[], t[];

    static StreamTokenizer in;
    static PrintWriter out;
    static double C32  = Math.log(3) / Math.log(2);
    static double C23  = Math.log(2) / Math.log(3);

    static int nextInt() throws IOException
   {
      in.nextToken();
      return (int)in.nval;
   }

    public static void count(int p[]) {
        dans[0] = 2;
        t[2] = p[2] - dans[2];
        t[3] = p[3] - dans[3];

        if (t[2] >= 0 && t[3] >= 0) {
            dans[2] = p[2];
            dans[3] = p[3];
        } else
        if (t[2] < 0 && t[3] < 0);
        else {
            if (t[2] == 0 || t[3] == 0);
            else {
                if (t[2] > 0 && t[3] < 0)
                {
                    if ((double)t[2] * C23 + (double)t[3] > 0) {
                        dans[2] = p[2];
                        dans[3] = p[3];
                    }
                } else
                if (t[2] < 0 && t[3] > 0)
                {
                    if ((double)t[3] * C32 + (double)t[2] > 0) {
                        dans[2] = p[2];
                        dans[3] = p[3];
                    }
                }
            }
        }
    }

    public static void main(String[] args) throws Exception {

            in = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
            PrintWriter print = new PrintWriter(System.out);

            BigInteger negStart, posStart;
            ans = BigInteger.ZERO;

            t = new int [4];
            dans = new int[4];
            dans[0] = 0; dans[1] = 0; dans[2] = 0; dans[3] = 0;

            int neg[] = new int[4];
            int pos[] = new int[4];
            neg[0] = 0; neg[1] = 0; neg[2] = 0; neg[3] = 0;
            pos[0] = 0; pos[1] = 0; pos[2] = 0; pos[3] = 0;

            int saveneg[] = new int[4];
            int savepos[] = new int[4];
            for(int j = 0; j < 4; j++) {
                saveneg[j] = neg[j];
                savepos[j] = pos[j];
            }

            int n = nextInt();
            int a, b = 0;

            for(int i = 1; i <= n; i++) {

                a = nextInt();
                if (i == 1) {
                    ans = BigInteger.valueOf(a);
                    b = a;
                } else if (b < a) b = a;

                if (neg[1] + neg[2] + neg[3] == 0 && a < 0) {
                    ++neg[-a];
                    neg[0] = 0;
                } else {
                    if (a == 0) {
                        // count
                        neg[0] = 0; neg[1] = 0; neg[2] = 0; neg[3] = 0;
                    } else
                    if (a < 0) {
                        ++neg[-a];
                        neg[0] = 2 - neg[0];
                    }
                    else if (neg[1] + neg[2] + neg[3] > 0) ++neg[a];
                }

                if (pos[1] + pos[2] + pos[3] == 0 && a > 0) {
                    ++pos[a];
                    pos[0] = 2;
                } else {
                    if (a == 0) {
                        // count
                        pos[0] = 0; pos[1] = 0; pos[2] = 0; pos[3] = 0;
                    } else
                        if (a < 0) {
                            if (pos[1] + pos[2] + pos[3] > 0) {
                                ++pos[-a];
                                pos[0] = 2 - pos[0];
                            }
                        } else ++pos[a];
                }

                if (neg[0] == 2) count(neg);
                if (pos[0] == 2) count(pos);

            }

            if (dans[0] == 2) {
                a2 = BigInteger.valueOf(2);
                a3 = BigInteger.valueOf(3);
                a2 = a2.pow(dans[2]);
                a3 = a3.pow(dans[3]);
                a2 = a2.multiply(a3);
                if (a2.compareTo(ans) > 0) ans = a2;
            }

            a2 = BigInteger.valueOf(b);
            if (ans.compareTo(a2) < 0) ans = a2;

            String r = ans.toString();
            System.out.println(r);
            print.close();

        }

    }