#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ld long double
#define EPS 1e-9
#define all(x) x.begin(),x.end()
#define allr(x) x.rbegin(),x.rend()
#define yes cout << "YES" << '\n';
#define no cout << "NO" << '\n';
#define mem(arrr, xx) memset(arrr,xx,sizeof arrr)
#define endl '\n'
#define PI acos(-1)
#define Ones(n) __builtin_popcount(n)
#define Onesl(n) __builtin_popcountll(n)
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
const ll MOD = 998244353;
const ll N = 2e5 + 5;
const int OO = 0x3f3f3f3f;
const ll LOO = 0x3f3f3f3f3f3f3f3f;
int dx8[] = {+0, +0, -1, +1, +1, +1, -1, -1};
int dy8[] = {-1, +1, +0, +0, +1, -1, +1, -1};
int dx4[] = {+0, +0, -1, +1};
int dy4[] = {-1, +1, +0, +0};

void Fast() {
    cin.tie(nullptr), cout.tie(nullptr), cin.sync_with_stdio(false), cout.sync_with_stdio(false);
#ifdef Clion
    freopen("input.txt", "r", stdin), freopen("output.txt", "w", stdout);
#endif
}
ll fac[N], inv[N];
ll mul(const ll &a, const ll &b){
    return (a % MOD + MOD) * (b % MOD + MOD) % MOD;
}

ll add(const ll &a, const ll &b){
    return (a + b + 2 * MOD) % MOD;
}

ll pw(ll b, ll p){
    if(p < 0)return 0;
    if(!p)return 1ll;
    ll ret = pw(b, p >> 1ll);
    ret = mul(ret, ret);
    if(p & 1){
        ret = mul(ret, b);
    }
    return ret;
}
void build(){
    fac[0] = 1;
    for (int i = 1; i < N; ++i) {
        fac[i] = mul(fac[i - 1], i);
    }
    inv[N - 1] = pw(fac[N - 1], MOD - 2);
    for (int i = N - 2; i >= 0; --i) {
        inv[i] = mul(inv[i + 1], i + 1);
    }
}

ll nCr(int n, int r){
    if(r > n)return 0;
    return mul(mul(fac[n], inv[n - r]), inv[r]);
}

void Solution() {
    ll n, m;
    cin >> n >> m;
    ll paths = nCr(n + m - 2, m - 1);
    paths = mul(paths, paths);
    ll bad = mul(nCr(n + m - 2, m - 2), nCr(n + m - 2, n - 2));
    ll ans = add(paths, -bad);
    cout << ans << '\n';
}

int main() {
    build();
    Fast();
    int T = 1;
//    cin >> T;
    while (T--) {
        Solution();
    }
}