MOD = 998244353

n = int(input())
a = input().strip()

ans = 1
i = 0

while i < n:
    j = i
    while j + 1 < n and not (a[j] == "1" and a[j + 1] == "0"):
        j += 1

    saw0 = False
    saw1 = False

    k = i
    while k <= j:
        if a[k] == "0":
            saw0 = True
        else:
            saw1 = True
        k += 1

    if saw0 and saw1:
        ans *= (j - i + 2)
        ans %= MOD

    i = j + 1

print(ans)