package main

import (
	"bufio"
	"fmt"
	"os"
)

func main() {
	const mod = 998244353
	in := bufio.NewReader(os.Stdin)
	var n int
	var s string
	fmt.Fscan(in, &n, &s)
	ans := 1
	i := 0
	for i < n {
		j := i
		for j < n && s[j] == s[i] {
			j++
		}
		if s[i] == '0' && j < n && s[j] == '1' {
			a := j - i
			k := j
			for k < n && s[k] == '1' {
				k++
			}
			b := k - j
			ans = int(int64(ans) * int64(a+b+1) % mod)
		}
		i = j
	}
	fmt.Println(ans)
}