#include using namespace std; using ll = long long; const ll modc=998244353, MAX=1000000; class mint { ll x; public: mint(ll x=0) : x((x%modc+modc)%modc) {} mint operator-() const { return mint(-x); } mint& operator+=(const mint& a) { if ((x += a.x) >= modc) x -= modc; return *this; } mint& operator-=(const mint& a) { if ((x += modc-a.x) >= modc) x -= modc; return *this; } mint& operator*=(const mint& a) { (x *= a.x) %= modc; return *this; } mint operator+(const mint& a) const { mint res(*this); return res+=a; } mint operator-(const mint& a) const { mint res(*this); return res-=a; } mint operator*(const mint& a) const { mint res(*this); return res*=a; } mint pow(ll t) const { if (!t) return 1; mint a = pow(t>>1); a *= a; if (t&1) a *= *this; return a; } mint inv() const { return pow(modc-2); } mint& operator/=(const mint& a) { return (*this) *= a.inv(); } mint operator/(const mint& a) const { mint res(*this); return res/=a; } bool operator == (const mint& a) const{ return x == a.x; } friend ostream& operator<<(ostream& os, const mint& m){ os << m.x; return os; } friend istream& operator>>(istream& ip, mint &m) { ll t; ip >> t; m = mint(t); return ip; } ll val(){ return x; } }; vector f, finv; mint inv(mint x){ mint ans = 1; ll e = modc-2; while (e > 0){ if ((e & 1LL)) ans *= x; e = e >> 1LL; x *= x; } return ans; } void init(){ f.resize(MAX+1); finv.resize(MAX+1); f[0] = 1; for (int i=1; i<=MAX; i++) f[i] = f[i-1]*i; finv[MAX] = inv(f[MAX]); for (int i=MAX-1; i>=0; i--) finv[i] = finv[i+1] * (i+1); } mint C(ll n, ll k){ if (n < k || k < 0) return 0; return f[n] * finv[k] * finv[n-k] ; } mint P(ll n, ll k){ if (n < k || k < 0) return 0; return f[n] * finv[n-k]; } mint H(ll n, ll k){ if (n == 0 && k == 0) return 1; return C(n+k-1, k); } int main(){ init(); int N, K; mint ans; cin >> N >> K; if (N == 1){ if (K == 1 || K == 5 || K == 6) cout << 1 << endl; else cout << 3 << endl; return 0; } if (N % 2 == 0){ ans = C(2*N+4, K) + (K % 2 == 0 ? C(N+2, K/2) * 3 : 0); ans /= 4; cout << ans << endl; } else{ ans = C(2*N+4, K) + (K % 2 == 0 ? C(N+2, K/2) * 2 : 0); ans += (K % 2 == 0 ? C(N+1, K/2) + C(N+1, K/2-1) : C(N+1, (K-1)/2) * 2); ans /= 4; cout << ans << endl; } return 0; }