import java.util.*;

public class Main{
        public static void main(String[] args){
                try(Scanner sc = new Scanner(System.in)){
                        int N = sc.nextInt(), num = 0, now;
                        for(int i = 0; i < N; i++){
                                now = Math.abs(sc.nextInt());
                                num = Math.max(num + now, num * now);
                        }
                        System.out.println(num);
                }
        }
}