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();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = NN;
        var a = NList;
        var mod = 998_244_353;
        var ans = 1L;
        for (var i = 1; i < n; ++i)
        {
            ans = ans * Math.Min(a[i - 1], a[i]) % mod;
        }
        WriteLine(ans);
    }
}