#line 2 "test.cpp"
#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
using ll = long long;
using ld = long double;
using pll = pair<ll, ll>;
using pii = pair<int, int>;
template<class T> using pq = priority_queue<T, vector<T>, greater<T>>;
#define overload4(_1, _2, _3, _4, name, ...) name
#define overload3(a,b,c,name,...) name
#define rep1(n) for (ll i = 0; i < (n); ++i)
#define rep2(i, n) for (ll i = 0; i < (n); ++i)
#define rep3(i, a, b) for (ll i = (a); i < (b); ++i)
#define rep4(i, a, b, c) for (ll i = (a); i < (b); i += (c))
#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)
#define rrep1(n) for(ll i = (n) - 1;i >= 0;i--)
#define rrep2(i,n) for(ll i = (n) - 1;i >= 0;i--)
#define rrep3(i,a,b) for(ll i = (b) - 1;i >= (a);i--)
#define rrep4(i,a,b,c) for(ll i = (a) + ((b)-(a)-1) / (c) * (c);i >= (a);i -= c)
#define rrep(...) overload4(__VA_ARGS__, rrep4, rrep3, rrep2, rrep1)(__VA_ARGS__)
#define all1(i) begin(i) , end(i)
#define all2(i,a) begin(i) , begin(i) + a
#define all3(i,a,b) begin(i) + a , begin(i) + b
#define all(...) overload3(__VA_ARGS__, all3, all2, all1)(__VA_ARGS__)
#define sum(...) accumulate(all(__VA_ARGS__),0LL)
template<class T> bool chmin(T &a, const T &b){ if(a > b){ a = b; return 1; } else return 0; }
template<class T> bool chmax(T &a, const T &b){ if(a < b){ a = b; return 1; } else return 0; }
template<class T> auto min(const T& a){ return *min_element(all(a)); }
template<class T> auto max(const T& a){ return *max_element(all(a)); }
template<class... Ts> void in(Ts&... t);
#define elif else if
#define vec(type,name,...) vector<type> name(__VA_ARGS__)
#define vv(type,name,h,...) vector<vector<type>>name(h,vector<type>(__VA_ARGS__))
#define INT(...) int __VA_ARGS__; in(__VA_ARGS__)
#define LL(...) ll __VA_ARGS__; in(__VA_ARGS__)
#define STR(...) string __VA_ARGS__; in(__VA_ARGS__)
#define CHR(...) char __VA_ARGS__; in(__VA_ARGS__)
#define DBL(...) double __VA_ARGS__; in(__VA_ARGS__)
#define LD(...) ld __VA_ARGS__; in(__VA_ARGS__)
#define VEC(type, name, size) vector<type> name(size); in(name)
#define VV(type, name, h, w) vector<vector<type>> name(h, vector<type>(w)); in(name)
ll intpow(ll a, ll b){ ll ans = 1; while(b){ if(b & 1) ans *= a; a *= a; b /= 2; } return ans; }
ll modpow(ll a, ll b, ll p){ ll ans = 1; while(b){ if(b & 1) (ans *= a) %= p; (a *= a) %= p; b /= 2; } return ans; }
namespace IO{
#define VOID(a) decltype(void(a))
struct setting{
    setting(){
        cin.tie(nullptr); ios::sync_with_stdio(false);
        fixed(cout); cout.precision(12);
    }
} setting;
template<int I> struct P : P<I-1>{};
template<> struct P<0>{};
template<class T> void i(T& t){ i(t, P<3>{}); }
void i(vector<bool>::reference t, P<3>){ int a; i(a); t = a; }
template<class T> auto i(T& t, P<2>) -> VOID(cin >> t){ cin >> t; }
template<class T> auto i(T& t, P<1>) -> VOID(begin(t)){ for(auto&& x : t) i(x); }
template<class T, size_t... idx> void ituple(T& t, index_sequence<idx...>){
    in(get<idx>(t)...);
}
template<class T> auto i(T& t, P<0>) -> VOID(tuple_size<T>{}){
    ituple(t, make_index_sequence<tuple_size<T>::value>{});
}

#undef VOID
}
#define unpack(a) (void)initializer_list<int>{(a, 0)...}
template<class... Ts> void in(Ts&... t){ unpack(IO :: i(t)); }


#undef unpack
#line 1 "library/modint.hpp"
template <int mod>
struct Modint{
    ll x;
    Modint():x(0) {}

    Modint(ll y): x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}
    
    Modint &operator += (const Modint &p) {
        if((x += p.x) >= mod) x -= mod;
        return *this;
    }
    Modint &operator -= (const Modint &p) {
        if ((x += mod - p.x) >= mod) x -= mod;
        return *this;
    }
    Modint &operator *= (const Modint &p) {
        x = x * p.x % mod;
        return *this;
    }
    Modint &operator /= (const Modint &p) {
        *this *= p.inverse();
        return *this;
    }
    Modint operator -() const{return Modint(-x);}
    Modint operator +(const Modint &p) const {return Modint(*this) += p;}
    Modint operator -(const Modint &p) const {return Modint(*this) -= p;}
    Modint operator *(const Modint &p) const {return Modint(*this) *= p;}
    Modint operator /(const Modint &p) const {return Modint(*this) /= p;}
    Modint &operator++() {if(x == mod - 1) x = 0; else x++; return *this;}
    Modint &operator--() {if(x == 0) x = mod - 1; else x--; return *this;} 
    bool operator == (const Modint &p) const {return x == p.x;}
    bool operator != (const Modint &p) const {return x != p.x;}
    Modint inverse() const {
        int a = x, b = mod, u = 1, v = 0, t;
        while (b > 0) {
            t = a / b;
            swap(a -= t * b, b);
            swap(u -= t * v, v);
        }
        return Modint(u);
    }
    Modint pow(ll n) const {
        Modint ret(1), mul(x);
        while (n > 0) {
            if (n & 1) ret *= mul;
            mul *= mul;
            n >>= 1;
        }
        return ret;
    }
};
#line 75 "test.cpp"
//constexpr mod = 1000000007;
constexpr int mod = 998244353;
using mint = Modint<mod>;
vector<mint> fact, fact_inv;
void make_fact(int n){
        fact.resize(n+1), fact_inv.resize(n+1);
        fact[0] = mint(1); rep(i,1,n+1) fact[i] = fact[i-1] * mint(i);
        fact_inv[n] = fact[n].inverse(); rrep(i,0,n) fact_inv[i] = fact_inv[i+1] * mint(i+1);
}
mint comb(int n, int k){ if(n < 0 || k < 0 || n < k) return mint(0); return fact[n] * fact_inv[k] * fact_inv[n-k];}
mint perm(int n, int k){ return comb(n, k) * fact[k]; }
int main() {
    INT(n,m);
    make_fact(400005);
    mint ans = comb(n+m-2,n-1);
    cout << ans.x << endl;
}