import sys
#sys.setrecursionlimit(5*10**5)
input = sys.stdin.readline
sys.set_int_max_str_digits(0)
from collections import defaultdict, deque, Counter
from heapq import heappop, heappush
from bisect import bisect_left, bisect_right
from math import gcd, lcm, factorial, perm, comb
from itertools import product, permutations
from functools import lru_cache #@lru_cache(maxsize=128)
#重複あり：list(product(list('123'),repeat = 2)),重複なし：list(permutations(list('123')))
MOD = 998244353

n = int(input())
l = list(input())
s=1
cnt=1
for i in range(n):
    if l[i]=='1':
        cnt+=1
        s*=cnt
        cnt=1
    else:
        cnt+=1
    s%=MOD
    #print(s)
print(s//3)