#include #include #include #include #include #include #include #include #include #include #include #include #include #include #define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl; #define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl; template inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } using namespace std; typedef long long ll; template vector> vec2d(int n, int m, T v){ return vector>(n, vector(m, v)); } template vector>> vec3d(int n, int m, int k, T v){ return vector>>(n, vector>(m, vector(k, v))); } template void print_vector(vector v, char delimiter=' '){ if(v.empty()) { cout << endl; return; } for(int i = 0; i+1 < v.size(); i++) cout << v[i] << delimiter; cout << v.back() << endl; } using mint = atcoder::modint998244353; ostream& operator<<(ostream& os, const mint& m){ os << m.val(); return os; } #define N_MAX 1000002 mint inv[N_MAX],fac[N_MAX],finv[N_MAX]; void init(){ const ll MOD = mint::mod(); fac[0]=1;fac[1]=1; finv[0]=1;finv[1]=1; inv[1]=1; for(int i=2;i> n >> k; if(n == 1){ if(k == 6) cout << 1 << endl; if(k == 1 || k == 5) cout << 1 << endl; if(k == 2 || k == 4) cout << 3 << endl; if(k == 3) cout << 3 << endl; return 0; } mint ans = comb(2*n+4, k); if(k%2 == 0){ ans += comb(n+2, k/2)*2; }else{ } if(n%2 == 0){ if(k%2 == 0){ ans += comb(n+2, k/2); }else{ } }else{ for(int x = 0; x <= 2; x++){ if(x%2 == k%2 && k >= x){ ans += comb(2, x)*comb(n+1, (k-x)/2); } } } ans /= 4; cout << ans << endl; }