"""

"""

import sys

N = int(input())

c = list(map(int,input().split()))

m = 0
z = 0
p = 0

for i in c:
    if i > 0:
        p += 1
    elif i == 0:
        z += 1
    else:
        m += 1

mod = 998244353

ans = pow(2,max(0,m-1),mod) * pow(2,max(0,p-1),mod)

if m > 0 and p > 0:
    ans *= 2
if z == 1:
    if m > 0 and p > 0:
        ans *= 3
    elif m+p > 0:
        ans *= 2
    else:
        ans *= 1

print (ans % mod)