func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MOD = 998244353;   long long int memo[1005][2005][4];   int n, k;   void solve() {     for (int i = 2; i <= n; i++) {       for (int j = 1; j <= i * 2; j++) {         memo[i][j][0] = (memo[i - 1][j][0] + memo[i - 1][j][1] +                          memo[i - 1][j][2] + memo[i - 1][j - 1][3]) %                         MOD;         memo[i][j][1] = (memo[i - 1][j - 1][0] + memo[i - 1][j][1] +                          memo[i - 1][j - 2][2] + memo[i - 1][j - 1][3]) %                         MOD;         memo[i][j][2] = (memo[i - 1][j - 1][0] + memo[i - 1][j - 2][1] +                          memo[i - 1][j][2] + memo[i - 1][j - 1][3]) %                         MOD;         memo[i][j][3] = (memo[i - 1][j - 1][0] + memo[i - 1][j][1] +                          memo[i - 1][j][2] + memo[i - 1][j][3]) %                         MOD;       }     }   }   int main() {     cin >> n >> k;     memo[1][1][0] = 1;     memo[1][2][1] = 1;     memo[1][2][2] = 1;     memo[1][1][3] = 1;     solve();     printf( %lld ,            (memo[n][k][0] + memo[n][k][1] + memo[n][k][2] + memo[n][k][3]) % MOD);   }   