import sys

def solve():
    input_data = sys.stdin.read().split()
    if len(input_data) < 2:
        return
    
    n = int(input_data[0])
    s = input_data[1]
    MOD = 998244353

    ans = 1
    i = 0
    while i < n:
        if s[i] == '0':
            c0 = 0
            while i < n and s[i] == '0':
                c0 += 1
                i += 1
            
            c1 = 0
            while i < n and s[i] == '1':
                c1 += 1
                i += 1
            
            if c1 > 0:
                ans = (ans * (c0 + c1)) % MOD
        else:
            i += 1
            
    print(ans)

if __name__ == "__main__":
    solve()