func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, k;   long long f[1005][2005][4];   int main() {     f[1][1][0] = f[1][1][1] = f[1][2][2] = f[1][2][3] = 1;     cin >> n >> k;     for (int i = 1; i <= n; i++) f[i][1][0] = f[i][1][1] = 1;     for (int i = 2; i <= n; i++) {       for (int j = 2; j <= k; j++) {         f[i][j][0] = (f[i - 1][j][0] + f[i - 1][j - 1][1] + f[i - 1][j][2] +                       f[i - 1][j][3]) %                      998244353;         f[i][j][1] = (f[i - 1][j - 1][0] + f[i - 1][j][1] + f[i - 1][j][2] +                       f[i - 1][j][3]) %                      998244353;         f[i][j][2] = (f[i - 1][j - 1][0] + f[i - 1][j - 1][1] + f[i - 1][j][2] +                       f[i - 1][j - 2][3]) %                      998244353;         f[i][j][3] = (f[i - 1][j - 1][0] + f[i - 1][j - 1][1] +                       f[i - 1][j - 2][2] + f[i - 1][j][3]) %                      998244353;       }     }     long long ans = 0;     for (int i = 0; i <= 3; i++) ans = (ans + f[n][k][i]) % 998244353;     cout << ans;   }   