#include <bits/stdc++.h>
// clang-format off
using namespace std; using ll=long long; using ull=unsigned long long; using pll=pair<ll,ll>; const ll INF=4e18;
void print0(){}; template<typename H,typename... T> void print0(H h,T... t){cout<<h;print0(t...);}
void print(){print0("\n");}; template<typename H,typename... T>void print(H h,T... t){print0(h);if(sizeof...(T)>0)print0(" ");print(t...);}
void perr0(){}; template<typename H,typename... T> void perr0(H h,T... t){cerr<<h;perr0(t...);}
void perr(){perr0("\n");}; template<typename H,typename... T>void perr(H h,T... t){perr0(h);if(sizeof...(T)>0)perr0(" ");perr(t...);}
void ioinit() { cout<<fixed<<setprecision(15); cerr<<fixed<<setprecision(6); ios_base::sync_with_stdio(0); cin.tie(0); }
// clang-format on

// 図形3の右下は図形1のみ
// 図形3の左上も図形1のみ
// 図形2の上下は図形1のみ
// 図形3の位置が右上がりになる感じ

// 一番下で、図形3の位置はa-1通り
// 高さは b-1
const ll MODULO = 998244353;
const ll COMBMAX = 200005;
ll fac[COMBMAX], finv[COMBMAX], inv[COMBMAX];
void combination_init() {
    fac[0] = fac[1] = 1;
    finv[0] = finv[1] = 1;
    inv[1] = 1;
    for (int i = 2; i < COMBMAX; i++) {
        fac[i] = fac[i - 1] * i % MODULO;
        inv[i] = MODULO - inv[MODULO % i] * (MODULO / i) % MODULO;
        finv[i] = finv[i - 1] * inv[i] % MODULO;
    }
}
ll combination(ll n, ll k) {
    if (n < k) return 0;
    if (n < 0 || k < 0) return 0;
    return fac[n] * (finv[k] * finv[n - k] % MODULO) % MODULO;
}
int main() {
    ioinit();
    ll a, b;
    cin >> a >> b;
    combination_init();
    print(combination(a + b - 2, b - 1));
    return 0;
}