# snippet: templete_
# Last Modified: 2026-02-13

from collections import deque, defaultdict
from itertools import permutations, product
from bisect import bisect_left, bisect_right
from heapq import heappush, heappop
from random import randint, shuffle
from time import perf_counter as pc
def II(): return int(input())
def LI(): return list(map(int,input().split()))
def LI_1(): return [int(x) - 1 for x in input().split()]
def SI(): return input()
def LS(): return list(input().split())
mod = 998244353
inf = 1001001001001001001

import sys
sys.setrecursionlimit(10 ** 6)
input = lambda: sys.stdin.readline().rstrip()
_buf = []
def print(*a, **k): _buf.append(" ".join(map(str, a)))


def solve():
    N = II()
    A = SI()
    ans = 1
    prev = -1
    cnt = 0
    res = 0
    for i in range(N):
        if prev == -1:
            prev = A[i]
            cnt = 1
        elif prev == A[i]:
            cnt += 1
        else:
            if A[i] == "1":
                res = cnt
            elif res != 0:
                ans = ans * (res + cnt + 1) % mod
            prev = A[i]
            cnt = 1
    if prev == "1" and res != 0:
        ans = ans * (res + cnt + 1) % mod
    print(ans)
    return

if __name__ == "__main__":
    T = 1
    # T = II()
    for _ in range(T):
        solve()
    sys.stdout.write("\n".join(_buf) + "\n")