MOD = 998244353

n = int(input())
C = list(map(int, input().split()))
p = 0
z = 0
m = 0
for c in C:
    if c > 0:
        p += 1
    elif c == 0:
        z += 1
    else:
        m += 1

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

if p > 0 and m > 0:
    ans *= 2

if p > 0:
    ans *= pow(2, p - 1, MOD)
if m > 0:
    ans *= pow(2, m - 1, MOD)

print(ans % MOD)