public class Test03 { public static void main(String[] args) { int dp[][] = new int[1000][1000];  Scanner scanner = new Scanner(System.in);  int n = scanner.nextInt();  int m = scanner.nextInt();   dp[0][1] = 1;  dp[1][n] = 1;  dp[1][2] = 1;  for (int i = 1; i < m; i++) { for (int j = 1; j < n; j++) { if (j == 1) { dp[i][j] = dp[i - 1][n] + dp[i - 1][2];  } else if (j == n) { dp[i][j] = dp[i - 1][1] + dp[i - 1][n - 1];  } else { dp[i][j] = dp[i - 1][j - 1] + dp[i - 1][j + 1];  }
            }
        }
        System.out.println(dp[m][1]);  }
}