using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
using System.Runtime.Intrinsics.Arm;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static string[] SList(long n) => Enumerable.Repeat(0, (int)n).Select(_ => ReadLine()).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = NN;
        var a = ReadLine();
        a = a.TrimStart('1').TrimEnd('0');
        if (a.Length == 0)
        {
            WriteLine(1);
            return;
        }
        var ans = 1L;
        var mod = 998_244_353;
        var prev = 0;
        for (var i = 0; i + 1 < a.Length; ++i)
        {
            if (a[i] == '1' && a[i + 1] == '0')
            {
                ans = ans * (i - prev + 2) % mod;
                prev = i + 1;
            }
        }
        ans = ans * (a.Length - prev + 1) % mod;
        WriteLine(ans);
    }
}