//* #pragma GCC target("avx2") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") //*/ #include // #include #include using namespace std; using namespace atcoder; // #define _GLIBCXX_DEBUG #define DEBUG(x) cerr << #x << ": " << x << endl; #define DEBUG_VEC(v) \ cerr << #v << ":"; \ for (int iiiiiiii = 0; iiiiiiii < v.size(); iiiiiiii++) \ cerr << " " << v[iiiiiiii]; \ cerr << endl; #define DEBUG_MAT(v) \ cerr << #v << endl; \ for (int iv = 0; iv < v.size(); iv++) { \ for (int jv = 0; jv < v[iv].size(); jv++) { \ cerr << v[iv][jv] << " "; \ } \ cerr << endl; \ } typedef long long ll; // #define int ll #define vi vector #define vl vector #define vii vector> #define vll vector> #define vs vector #define pii pair #define pis pair #define psi pair #define pll pair template pair operator+(const pair &s, const pair &t) { return pair(s.first + t.first, s.second + t.second); } template pair operator-(const pair &s, const pair &t) { return pair(s.first - t.first, s.second - t.second); } template ostream &operator<<(ostream &os, pair p) { os << "(" << p.first << ", " << p.second << ")"; return os; } #define X first #define Y second #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define rep1(i, n) for (int i = 1; i <= (int)(n); i++) #define rrep(i, n) for (int i = (int)(n)-1; i >= 0; i--) #define rrep1(i, n) for (int i = (int)(n); i > 0; i--) #define REP(i, a, b) for (int i = a; i < b; i++) #define in(x, a, b) (a <= x && x < b) #define all(c) c.begin(), c.end() void YES(bool t = true) { cout << (t ? "YES" : "NO") << endl; } void Yes(bool t = true) { cout << (t ? "Yes" : "No") << endl; } void yes(bool t = true) { cout << (t ? "yes" : "no") << endl; } void NO(bool t = true) { cout << (t ? "NO" : "YES") << endl; } void No(bool t = true) { cout << (t ? "No" : "Yes") << endl; } void no(bool t = true) { cout << (t ? "no" : "yes") << endl; } template bool chmax(T &a, const T &b) { if (a < b) { a = b; return 1; } return 0; } template bool chmin(T &a, const T &b) { if (a > b) { a = b; return 1; } return 0; } #define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end()); const ll inf = 1000000001; const ll INF = (ll)1e18 + 1; const long double pi = 3.1415926535897932384626433832795028841971L; int popcount(ll t) { return __builtin_popcountll(t); } // int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1}; // int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 }; vi dx = {0, 0, -1, 1}, dy = {-1, 1, 0, 0}; vi dx2 = {1, 1, 0, -1, -1, -1, 0, 1}, dy2 = {0, 1, 1, 1, 0, -1, -1, -1}; struct Setup_io { Setup_io() { ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0); cout << fixed << setprecision(25); } } setup_io; // const ll MOD = 1000000007; const ll MOD = 998244353; // #define mp make_pair //#define endl '\n' using mint = modint998244353; class UnionFind { private: vi par_; //�e vi ran_; //�؂̐[�� vi num_; //�v�f�� vi edge_num_; //�v�f�� public: int n; int g; // group�� UnionFind(int _n) { n = _n; g = n; par_.resize(n); ran_.resize(n); num_.resize(n); edge_num_.resize(n); for (int i = 0; i < n; i++) { par_[i] = i; ran_[i] = 0; num_[i] = 1; edge_num_[i] = 0; } } //�؂̍������߂� int find(int x) { if (par_[x] == x) { return x; } else { return par_[x] = find(par_[x]); } } //x��y�̑�����W���𕹍� void unite(int x, int y) { x = find(x); y = find(y); int numsum = num_[x] + num_[y]; int edge_numsum = edge_num_[x] + edge_num_[y]; if (x == y) { edge_num_[x]++; return; } if (ran_[x] < ran_[y]) { par_[x] = y; } else { par_[y] = x; if (ran_[x] == ran_[y]) { ran_[x]++; } } num_[x] = num_[y] = numsum; edge_num_[x] = edge_num_[y] = edge_numsum + 1; g--; } //x��y�������W���ɑ����邩�ۂ� bool same(int x, int y) { return find(x) == find(y); } int num(int x) { return num_[find(x)]; } int edge_num(int x) { return edge_num_[find(x)]; } }; int n, k; mint solve(bool rotate, bool flip1, bool flip2) { int V = 2 * n + 4; int M = n + 2; UnionFind uf(V); if (rotate) { rep(i, V) { uf.unite(i, V - 1 - i); } } if (flip1) { rep(i, M) { uf.unite(i, M - 1 - i); uf.unite(M + i, 2 * M - 1 - i); } } if (flip2) { rep(i, M) { uf.unite(i, i + M); } } queue> fs; rep(i, V) { if (uf.find(i) != i) { continue; } int sz = uf.num(i); vector f(sz + 1); f[0] = f[sz] = 1; fs.push(f); } while (fs.size() > 1) { auto f1 = fs.front(); fs.pop(); auto f2 = fs.front(); fs.pop(); auto f = convolution(f1, f2); fs.push(f); } auto ret = fs.front(); return ret[k]; } signed main() { cin >> n >> k; mint ans = 0; rep(i, 4) { mint ret = solve(i == 3, i == 2, i == 1); DEBUG(ret.val()); ans += ret; } cout << (ans / 4).val() << endl; }