#include <iostream>
#include <vector>
using namespace std;
typedef long long ll;

const ll MOD = 998244353;

long long modpow(long long x, long long n)
{
    long long res = 1;
    long long mul = x;
    while (n)
    {
        if (n % 2)
            res = res * mul % MOD;
        mul = mul * mul % MOD;
        n /= 2;
    }
    return res;
}

struct Combination
{
    int maxn;
    std::vector<long long> fact;
    std::vector<long long> ifact;

    Combination(int maxn) : maxn(maxn)
    {
        fact.resize(maxn + 1);
        ifact.resize(maxn + 1);
        fact[0] = 1;
        for (int i = 1; i <= maxn; i++)
            fact[i] = fact[i - 1] * i % MOD;
        ifact[maxn] = modpow(fact[maxn], MOD - 2);
        for (int i = maxn - 1; i >= 0; i--)
            ifact[i] = ifact[i + 1] * (i + 1) % MOD;
    }

    long long com(int n, int k)
    {
        if (k > n || k < 0)
            return 0;
        return (fact[n] * ifact[k] % MOD) * ifact[n - k] % MOD;
    }
};

int main()
{
    ll n, m;
    cin >> n >> m;
    ll s = 1;
    for (int i = m + n * 2; i >= m; i--)
    {
        s = s * i % MOD;
    }
    for (int i = n * 2; i > 0; i--)
    {
        s = s * modpow(i, MOD - 2) % MOD;
    }
    cout << s * n % MOD * modpow(n * 2 + 1, MOD - 2) % MOD << endl;
}