import java.io.*; import java.util.*; import java.util.stream.*; public class Main { public static void main(String[] args) throws Exception { Scanner sc = new Scanner(); int n = sc.nextInt(); long min = sc.nextInt(); long max = min; for (int i = 1; i < n; i++) { int x = sc.nextInt(); long nMin = Long.MAX_VALUE; long nMax = Long.MIN_VALUE; nMin = Math.min(nMin, min + x); nMin = Math.min(nMin, max + x); nMin = Math.min(nMin, min - x); nMin = Math.min(nMin, max - x); nMin = Math.min(nMin, min * x); nMin = Math.min(nMin, max * x); if (x != 0) { nMin = Math.min(nMin, min / x); nMin = Math.min(nMin, max / x); } nMax = Math.max(nMax, min + x); nMax = Math.max(nMax, max + x); nMax = Math.max(nMax, min - x); nMax = Math.max(nMax, max - x); nMax = Math.max(nMax, min * x); nMax = Math.max(nMax, max * x); if (x != 0) { nMax = Math.max(nMax, min / x); nMax = Math.max(nMax, max / x); } min = nMin; max = nMax; } System.out.println(max); } } class Utilities { static String arrayToLineString(Object[] arr) { return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n")); } static String arrayToLineString(int[] arr) { return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new)); } } class Scanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); StringBuilder sb = new StringBuilder(); public Scanner() throws Exception { } public int nextInt() throws Exception { return Integer.parseInt(next()); } public long nextLong() throws Exception { return Long.parseLong(next()); } public double nextDouble() throws Exception { return Double.parseDouble(next()); } public int[] nextIntArray() throws Exception { return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray(); } public String next() throws Exception { while (!st.hasMoreTokens()) { st = new StringTokenizer(br.readLine()); } return st.nextToken(); } }