#include namespace { #pragma GCC diagnostic ignored "-Wunused-function" #include #pragma GCC diagnostic warning "-Wunused-function" using namespace std; using namespace atcoder; #define rep(i,n) for(int i = 0; i < (int)(n); i++) #define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--) #define all(x) begin(x), end(x) #define rall(x) rbegin(x), rend(x) template bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; } template bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; } using ll = long long; using P = pair; using VI = vector; using VVI = vector; using VL = vector; using VVL = vector; using mint = modint998244353; } int main() { ios::sync_with_stdio(false); cin.tie(0); int n, m; cin >> n >> m; vector> f(n + 1); vector> acc(n + 1); acc[0] = {1}; for (int i = 0; i <= n; i++) { vector g = acc[i]; // rep(j, i) { // g = convolution(f[j], g); // if (ssize(g) >= m + 1) g.resize(m + 1); // } if (i == n) { g.resize(m + 1); cout << g[m].val() << '\n'; exit(0); } g.insert(g.begin(), 1); if (ssize(g) >= m + 1) g.resize(m + 1); f[i] = g; acc[i + 1] = convolution(acc[i], f[i]); if (ssize(acc[i + 1])) acc[i + 1].resize(m + 1); } // vector g{1}; // rrep(i, n) { // g = convolution(g, f[i]); // if (ssize(g) >= m + 1) g.resize(m + 1); // } // g.resize(m + 1); // cout << g[m].val() << '\n'; }