import sys,random,bisect
from collections import deque,defaultdict
from heapq import heapify,heappop,heappush
from itertools import permutations
from math import gcd,log

input = lambda :sys.stdin.readline().rstrip()
mi = lambda :map(int,input().split())
li = lambda :list(mi())

mod = 998244353

def solve(N,S):
    dp = [0] * (N+1)
    dp[0] = 1
    for idx,s in enumerate(S):
        ndp = [0] * (N+2)
        for i in range(N+1):
            if not dp[i]: continue

            if s == '0':
                #ndp[i+1] += i * dp[i] % mod
                #ndp[i+1] %= mod
                ndp[i+1] += i * dp[i] % mod
                ndp[i+2] -= i * dp[i] % mod
                ndp[i+1] %= mod
                ndp[i+2] %= mod

                ndp[i+1] += dp[i]
                ndp[idx+2] -= dp[i]
                ndp[i+1] %= mod
                ndp[idx+2] %= mod
                #for j in range(i+1,idx+2):
                    #ndp[j] += dp[i]
                    #ndp[j] %= mod
            
            else:
                ndp[i] += dp[i] * (idx-i+1) % mod
                ndp[i] %= mod
                ndp[i+1] -= dp[i] * (idx-i+1) % mod
                ndp[i+1] %= mod

        dp = ndp
        for i in range(1,N+1):
            dp[i] += dp[i-1]
            dp[i] %= mod
    
    return sum(dp) % mod


def brute(N,S):
    res = 0
    for p in permutations([i for i in range(N)]):
        flg = 1
        for i in range(N):
            for j in range(i+1,N):
                if S[i] == '0' and S[j] == '1' and p[i] > p[j]:
                    flg = 0
        res += flg
    return res

N = int(input())
#S = "".join([random.choice("01") for i in range(N)])
S = input()
print(solve(N,S))