import collections,sys,math,functools,operator,itertools,bisect,heapq,decimal,string,time,random
#sys.setrecursionlimit(10**9)rg
# (itertools.prrange(n)):
"""
n = 5
s = set()
for i in range(1<<n):
    a,b = [],[]
    for j in range(n):
        if(i >> j) & 1 == 0:
            a.append(j)
        else:
            b.append(j)
    b.reverse()
    a += b
    s.add(tuple(a))
print(len(s))
exit()
"""

n = int(input())
a = list(map(int,input().split()))
#alist = []
#s = input()
#n,m = map(int,input().split())
#for i in range(n):
#    alist.append(list(map(int,input().split())))
def f(r):
    if r <= 1:
        return 1
    else:
        return pow(2,r-1,mod)
x,y,z = 0,0,0
for i in a:
    if i < 0:
        x += 1
    if i == 0:
        y += 1
    if i > 0:
        z += 1

mod = 998244353
ans = f(x) * f(z)
if x > 0 and z > 0:
    ans *= 2
if y == 1:
    ans *= (1 + min(1,x) + min(1,z))
print(ans % mod)