import sys

def solve():
    input_data = sys.stdin.read().split()
    if not input_data:
        return
    
    n = int(input_data[0])
    s = input_data[1]
    mod = 998244353

    ans = 1
    i = 0
    while i < n - 1:
        if s[i] == '0' and s[i+1] == '1':
            count = 0
            temp_i = i
            while temp_i < n - 1 and s[temp_i] == '0' and s[temp_i+1] == '1':
                count += 1
                temp_i += 2
            
            ans = (ans * (2 * count + 1)) % mod
            i = temp_i
        else:
            i += 1
            
    print(ans)

if __name__ == "__main__":
    solve()