import sys
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#####################################################################

"""

1100

010
110
000


"""

n = ni()
s = input()
if all(x == s[0] for x in s):
    print(1)
    exit()

mod = 998244353
i = 0
ans = 1
while i < n:
    # print(i)
    j = i
    while j < n and s[j] == "0":
        j += 1
    while j < n and s[j] == "1":
        j += 1
    ans *= j - i + 1
    ans %= mod
    i = j

print(ans)