from sys import stdin
n, *b = map(int, stdin.read().split())
p = 998244353

def powmod(n,pow,mod):
    val = 1
    while pow > 0:
        if pow & 1:
            val = (val * n) % mod
        pow = pow >> 1
        n = (n * n) % mod
    return val

numof2 = [0 for i in range(n+1)]
val = 2
while val <= n:
    kari = val
    while kari <= n:
        numof2[kari] += 1
        kari += val
    val = val * 2

kaijo = [0 for i in range(n+1)]
for i in range(1,n+1):
    kaijo[i] = kaijo[i-1] + numof2[i]

nowans = 0
oddnum = 0
evennum = 0
for i in range(n):
    kari = kaijo[n-1] - kaijo[i] - kaijo[n-1-i]
    if kari >= 1:
        if b[i] == -1:
            evennum += 1
    else:
        if b[i] == -1:
            oddnum += 1
        else:
            nowans = nowans ^ b[i]

if oddnum == 0:
    if nowans == 0:
        print("{}".format(0))
    else:
        ans = powmod(2,evennum,p)
        print("{}".format(ans))
else:
    ans = powmod(2,evennum+oddnum-1,p)
    print("{}".format(ans))