Mod = 998244353
N = int(input())
A = list(input())
A = ["1"] + A
while len(A) > 0 and A[-1] == "0":
    A.pop()
ans = 1
c0 = 0
c1 = 0
is_one = True
for i in range(len(A) - 1, -1, -1):
    # print(c1, c0, A, A[i])
    if(is_one):
        if(A[i] == "1"):
            c1 += 1
        else:
            is_one = False
            c0 += 1
    else:
        if(A[i] == "0"):
            c0 += 1
        else:

            ans *= (c1 + c0 + 1)
            ans %= Mod
            is_one = True
            c0 = 0
            c1 = 1
print(ans)