mod = 998244353
N = int(input())
C = list(map(int, input().split()))
x, y, z = 0, 0, 0
if 0 in C:
  z += 1
if max(C) > 0:
  x += 1
if min(C) < 0:
  y += 1

ans = pow(2, N - x - y - z, mod) * (x + y) * pow(x + y + z, z, mod) % mod
if N == 1:
  ans = 1
print(ans)