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

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        long max = sc.nextInt();
        long min = max;
        for (int i = 1; i < n; i++) {
            long nextMax = Long.MIN_VALUE;
            long nextMin = Long.MAX_VALUE;
            int x = sc.nextInt();
            nextMax = Math.max(nextMax, max * x);
            nextMax = Math.max(nextMax, max + x);
            nextMax = Math.max(nextMax, max - x);
            nextMax = Math.max(nextMax, min * x);
            nextMax = Math.max(nextMax, min + x);
            nextMax = Math.max(nextMax, min - x);
            nextMin = Math.min(nextMin, max * x);
            nextMin = Math.min(nextMin, max + x);
            nextMin = Math.min(nextMin, max - x);
            nextMin = Math.min(nextMin, min * x);
            nextMin = Math.min(nextMin, min + x);
            nextMin = Math.min(nextMin, min - x);
            max = nextMax;
            min = nextMin;
        }
        System.out.println(max);
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public String nextLine() throws Exception {
        return br.readLine();
    }
    
    public String next() throws Exception {
        if (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
}