def solve():
    N = int(input())
    A = input()
    
    MOD = 998244353
    ans = 1
    
    current_length = 0
    has_zero = False
    has_one = False
    
    for i in range(N):
        current_length += 1
        
        if A[i] == '0':
            has_zero = True
        if A[i] == '1':
            has_one = True
            
        if A[i] == '1' and i + 1 < N and A[i+1] == '0':
            if has_zero and has_one:
                ans = (ans * (current_length + 1)) % MOD
            
            current_length = 0
            has_zero = False
            has_one = False
            
    if has_zero and has_one:
        ans = (ans * (current_length + 1)) % MOD
        
    print(ans)

if __name__ == '__main__':
    solve()