import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] c = new int[n];
		for (int i = 0; i < n; i++) {
			c[i] = sc.nextInt();
		}
		sc.close();

		int m = 0;
		int z = 0;
		int p = 0;
		for (int i = 0; i < n; i++) {
			if (c[i] < 0) {
				m++;
			} else if (c[i] == 0) {
				z++;
			} else {
				p++;
			}
		}

		int mod = 998244353;
		int a = 1;
		if (m > 0 && p > 0) a++;
		int b = 1;
		if (m > 0) b++;
		if (p > 0) b++;
		if (z == 0) b = 1;

		long v1 = power(2, Math.max(m - 1, 0), mod);
		long v2 = power(2, Math.max(p - 1, 0), mod);
		long ans = a * v1 * b % mod * v2 % mod;
		System.out.println(ans);
	}

	static long power(long x, long n, int m) {
		if (n == 0) {
			return 1;
		}
		long val = power(x, n / 2, m);
		val = val * val % m;
		if (n % 2 == 1) {
			x %= m;
			val = val * x % m;
		}
		return val;
	}
}