#include <bits/stdc++.h>
using namespace std;
using ll = long long;
ll m = 998244353;
ll mpow(ll a, ll n) {
    ll ret = 1;
    while (n) {
        if (n & 1) {
            ret *= a;
            ret %= m;
        }
        n >>= 1;
        a = (a * a) % m;
    }
    return ret;
}
int main () {
    int a, b;
    cin >> a >> b;
    vector<ll> kai(a + b + 1, 1);
    for (int i = 1; i <= a + b; i ++) {
        kai[i] = kai[i - 1] * i;
        kai[i] %= m;
    }
    cout << (((kai[a + b - 2] * mpow(kai[a - 1], m - 2)) % m) * mpow(kai[b - 1], m - 2)) % m << endl;
}