func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, k, a, rev[132001 * 2], g[2][132001 * 2], ntt[132001], v1[132001],       v2[132001], fr[132001], ifr[132001], as[132001], fg = 255, inv[132001],                                                        vl[132001];   int pw(int a, int p) {     int as = 1;     while (p) {       if (p & 1) as = 1ll * as * a % 998244353;       a = 1ll * a * a % 998244353;       p >>= 1;     }     return as;   }   void init(int d) {     fr[0] = 1;     for (int i = 1; i <= 1 << d; i++) fr[i] = 1ll * fr[i - 1] * i % 998244353;     ifr[1 << d] = pw(fr[1 << d], 998244353 - 2);     for (int i = (1 << d); i >= 1; i--)       ifr[i - 1] = 1ll * ifr[i] * i % 998244353,               inv[i] = 1ll * fr[i - 1] * ifr[i] % 998244353;     for (int i = 2; i <= 1 << d; i <<= 1)       for (int j = 0; j < i; j++)         rev[i + j] = (rev[i + (j >> 1)] >> 1) + (j & 1 ? i >> 1 : 0);     for (int t = 0; t < 2; t++)       for (int i = 2; i <= 1 << d; i <<= 1) {         int tp = pw(3, 998244353 - 1 + (998244353 - 1) * (t * 2 - 1) / i);         for (int j = 0, vl = 1; j < (i >> 1); j++, vl = 1ll * vl * tp % 998244353)           g[t][i + j] = vl;       }   }   void dft(int s, int *a, int t) {     for (int i = 0; i < s; i++) ntt[rev[s + i]] = a[i];     for (int l = 2; l <= s; l <<= 1)       for (int i = 0; i < s; i += l)         for (int j = i, st = l; j < i + (l >> 1); j++, st++) {           int v1 = ntt[j], v2 = 1ll * ntt[j + (l >> 1)] * g[t][st] % 998244353;           ntt[j] = (v1 + v2) % 998244353;           ntt[j + (l >> 1)] = (v1 - v2 + 998244353) % 998244353;         }     int tp = t ? 1 : pw(s, 998244353 - 2);     for (int i = 0; i < s; i++) a[i] = 1ll * ntt[i] * tp % 998244353;   }   vector<int> add(vector<int> a, vector<int> b) {     vector<int> c;     int s1 = a.size(), s2 = b.size();     for (int i = 0; i < s1 || i < s2; i++)       c.push_back(((i < s1 ? a[i] : 0) + (i < s2 ? b[i] : 0)) % 998244353);     return c;   }   vector<int> mul(vector<int> a, vector<int> b, int n = 1e7) {     vector<int> c;     int s1 = a.size(), s2 = b.size();     for (int i = 0; i < s1 + s2 - 1; i++) c.push_back(0);     if (s1 + s2 <= fg) {       for (int i = 0; i < s1; i++)         for (int j = 0; j < s2; j++)           c[i + j] = (c[i + j] + 1ll * a[i] * b[j]) % 998244353;       while (c.size() > n) c.pop_back();       return c;     }     int l = 1;     while (l <= s1 + s2) l <<= 1;     for (int i = 0; i < l; i++) v1[i] = v2[i] = 0;     for (int i = 0; i < s1; i++) v1[i] = a[i];     for (int i = 0; i < s2; i++) v2[i] = b[i];     dft(l, v1, 1);     dft(l, v2, 1);     for (int i = 0; i < l; i++) v1[i] = 1ll * v1[i] * v2[i] % 998244353;     dft(l, v1, 0);     for (int i = 0; i < s1 + s2 - 1; i++) c[i] = v1[i];     while (c.size() > n) c.pop_back();     return c;   }   vector<int> polyinv(vector<int> a, int n) {     while (a.size() < n) a.push_back(0);     vector<int> b;     for (int i = 0; i < n; i++) b.push_back(0);     int tp = min(n, fg), st = pw(a[0], 998244353 - 2);     for (int i = 0; i < tp; i++) {       int vl = i ? 0 : 1;       for (int j = 0; j < i; j++)         vl = (vl - 1ll * b[j] * a[i - j] % 998244353 + 998244353) % 998244353;       b[i] = 1ll * vl * st % 998244353;     }     if (n <= fg) return b;     int x = 0;     while ((n >> x) >= fg * 2 - 1) x++;     while (1) {       int l1 = ((n - 1) >> x) + 1, l2 = (l1 >> 1) + 1, l = 1;       while (l <= l1 * 2 + 4) l <<= 1;       for (int i = 0; i < l; i++) v1[i] = v2[i] = 0;       for (int i = 0; i < l1; i++) v1[i] = a[i];       for (int i = 0; i < l2; i++) v2[i] = b[i];       dft(l, v1, 1);       dft(l, v2, 1);       for (int i = 0; i < l; i++)         v1[i] = 1ll * v2[i] * (2 - 1ll * v1[i] * v2[i] % 998244353 + 998244353) %                 998244353;       dft(l, v1, 0);       for (int i = 0; i < l1; i++) b[i] = v1[i];       if (!x) return b;       x--;     }   }   vector<int> polyln(vector<int> a, int n) {     vector<int> v1, v2 = polyinv(a, n), as;     for (int i = 1; i < a.size() && i <= n; i++)       v1.push_back(1ll * a[i] * i % 998244353);     v1 = mul(v1, v2);     as.push_back(0);     for (int i = 0; i < n; i++)       as.push_back(1ll * v1[i] * inv[i + 1] % 998244353);     return as;   }   int main() {     init(17);     scanf( %d%d , &n, &k);     int m = k / 2;     vl[0] = 1;     for (int i = 1; i <= n; i++)       if (i & 1)         vl[i] = 1ll * vl[i - 1] * inv[i] % 998244353 * (m - i / 2) % 998244353;       else         vl[i] = 1ll * vl[i - 1] * inv[i] % 998244353 * (m + i / 2) % 998244353;     vector<int> s1, s2;     for (int i = 0; i <= n; i++) s1.push_back(i & 1 ? 0 : vl[i]);     for (int i = 0; i <= n; i++) s2.push_back(i & 1 ? vl[i] : 0);     s2[0] = 998244353 - 1;     vector<int> t1 = mul(s2, polyinv(s1, n + 1), n + 1);     for (int i = 0; i <= n; i++)       if ((i + 3) % 4 > 1) t1[i] = (998244353 - t1[i]) % 998244353;     if (k & 1) t1[1] = (t1[1] + 1) % 998244353;     for (int i = 1; i <= n; i++)       t1[i] = (i & 1) * (998244353 - t1[i]) % 998244353;     vector<int> f1 = polyln(t1, n + 1);     int as = 1ll * n * (998244353 - f1[n]) % 998244353;     if (~n & 1) {       for (int i = 2; i <= n; i++)         if (i % 4 == 2) s1[i] = (998244353 - s1[i]) % 998244353;       s1 = polyln(s1, n + 1);       as = (as + 1ll * n * (998244353 - s1[n]) % 998244353) % 998244353;     }     printf( %d n , as);   }   