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 void Main()
    {
        var c = NList;
        var mod = 998_244_353;
        var ncr = new NCR(c[0] + c[1] - 2, mod);
        WriteLine(ncr.Calc(c[0] + c[1] - 2, c[0] - 1));
    }
    class NCR
    {
        int[] facts;
        int[] revFacts;
        int mod;
        public NCR(int n, int mod)
        {
            facts = new int[n + 1];
            revFacts = new int[n + 1];
            this.mod = mod;
            facts[0] = 1;
            var tmp = 1L;
            for (var i = 1; i <= n; ++i)
            {
                tmp = (tmp * i) % mod;
                facts[i] = (int)tmp;
            }
            tmp = Exp(facts[n], mod - 2);
            revFacts[n] = (int)tmp;
            for (var i = n; i > 1; --i)
            {
                tmp = (tmp * i) % mod;
                revFacts[i - 1] = (int)tmp;
            }
            revFacts[0] = 1;
        }
        long Exp(long n, long k)
        {
            n = n % mod;
            if (k == 0) return 1;
            if (k == 1) return n;
            var half = Exp(n, k / 2);
            var result = (half * half) % mod;
            return ((k % 2) == 0) ? result : ((result * n) % mod);
        }
        public int Calc(int n, int r)
        {
            if (r == 0 || r == n) return 1;
            if (r == 1) return n;
            return (int)(((long)facts[n] * revFacts[r] % mod) * revFacts[n - r] % mod);
        }
        public int Calc2(int n, int r)
        {
            var tmp = 1L;
            for (var i = 0; i < r; ++i)
            {
                tmp = tmp * (n - i) % mod;
            }
            return (int)(tmp * revFacts[r] % mod);
        }
        public int Fact(int n)
        {
            return facts[n];
        }
    }
}