MOD = 998244353

def RLE(A):
    ans = []
    cnt = 0
    for i in range(len(A)):
        cnt += 1
        if i+1 == len(A) or A[i] != A[i+1]:
            ans.append((A[i], cnt))
            cnt = 0
    return ans

def RLER(A):
    ans = []
    for s, c in A:
        ans.append(s*c)
    return "".join(ans)

N = int(input())
S = input()

R = RLE(S)
ans = 1
for i in range(len(R)-1):
    if R[i][0] == "0":
        ans *= R[i][1]+R[i+1][1]+1
        ans %= MOD

print(ans)