#include <bits/stdc++.h>   using namespace std;   const long long mod = 998244353;   const int maxn = 1100;   const int maxk = 2 * maxn;   long long dp[maxn][maxk][4];   long long st[4][4] = {{0, 1, 1, 1}, {1, 0, 1, 1}, {0, 0, 0, 2}, {0, 0, 2, 0}};   int main() {     int n, k;     scanf( %d%d , &n, &k);     dp[1][1][0] = 1;     dp[1][1][1] = 1;     dp[1][2][2] = 1;     dp[1][2][3] = 1;     for (int i = 2; i <= n; i++)       for (int j = 1; j <= k; j++)         for (int a = 0; a < 4; a++)           for (int b = 0; b < 4; b++)             dp[i][j + st[b][a]][a] += dp[i - 1][j][b] % mod;     printf( %d n , (dp[n][k][0] + dp[n][k][1] + dp[n][k][2] + dp[n][k][3]) % mod);     return 0;   }   