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(); } }