import java.util.Scanner;

public class HourGlass {

  /*
   * 1 1 1 0 0 0
   * 0 1 0 0 0 0
   * 1 1 1 0 0 0
   * 0 0 0 0 0 0
   * 0 0 0 0 0 0
   * 0 0 0 0 0 0
   */

  public static void main(String[] args) {
    int[][] ar = matrix();
    System.out.println(sumInt(ar));
  }

  private static int[][] matrix() {
    Scanner scanner = new Scanner(System.in);
    System.out.println("Please enter the 2D Matrix elements below:");
    System.out.println("Numbers of rows: ");
    int rows = scanner.nextInt();
    System.out.println("Numbers of Columns: ");
    int columns = scanner.nextInt();
    int[][] ar = new int[rows][columns];
    for (int i = 0; i < rows; i++) {
      for (int j = 0; j < columns; j++) {
        ar[i][j] = scanner.nextInt();
      }
      System.out.println();
    }
    for (int i = 0; i < rows; i++) {
      for (int j = 0; j < columns; j++) {
        System.out.print(ar[i][j] + "\t");
      }
      System.out.println();
    }
    scanner.close();
    return ar;
  }

  private static int sumInt(int[][] arr) {
    int rows = arr.length;
    int columns = arr[0].length;

    int total = -63;
    for (int i = 0; i < rows - 2; i++) {
      for (int j = 0; j < columns - 2; j++) {
        int currentSum = arr[i][j] + arr[i][j + 1] + arr[i][j + 2] + arr[i + 1][j + 1] + arr[i + 2][j]
            + arr[i + 2][j + 1] + arr[i + 2][j + 2];
        total = Math.max(total, currentSum);
      }
    }
    return total;
  }

}