using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = NN;
        var p = NList;
        WriteLine(Mex(n, p));
    }
    static long Mex(int n, int[] p)
    {
        var pos = new int[n];
        for (var i = 0; i < n; ++i) pos[p[i]] = i;
        var left = n + 1;
        var right = -1;
        var ans = 1L;
        var mod = 998_244_353;
        for (var i = 0; i < n; ++i)
        {
            var cnt = 1;
            if (left <= pos[i] && pos[i] <= right)
            {
                cnt = right - left - i + 1;
            }
            if (pos[i] < left)
            {
                left = pos[i];
            }
            if (right < pos[i])
            {
                right = pos[i];
            }
            ans = ans * cnt % mod;
        }
        return ans;
    }
}