import java.util.Scanner;
public class CardSushiki {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner s = new Scanner(System.in);
		int N = s.nextInt();
		int ans = 0,sub = 0,min = 0;;
		int[] a = new int[N];
		for(int i = 0;i < N;i++){
			a[i] = s.nextInt();
			if(a[i] < 0){
				sub++;
				if(min == 0){
					min = a[i];
				}else{
					min = Math.max(a[i], min);
				}
			}
		}
		if(sub % 2 == 0){
			for(int i = 0;i < N;i++){
				if(a[i] == 0||a[i] == -1){
					ans -= a[i];
				}else if(a[i] == 1){
					ans += a[i];
				}else{
					if(ans == 0){
						ans = 1;
					}
					ans *= a[i];
				}
			}
		}else{
			for(int i = 0;i < N;i++){
				if(a[i] == 0||a[i] == -1||a[i] == min){
					ans -= a[i];
				}else if(a[i] == 1){
					ans += a[i];
				}else{
					if(ans == 0){
						ans = 1;
					}
					ans *= a[i];
				}
			}
		}
		s.close();
		System.out.println(ans);

	}

}