public static int getBiggestRegion(int[][] matrix) {
        int max = 0;
        for (int i = 0; i < matrix.length; i++) {
            for (int j = 0; j < matrix[0].length; j++) {
                max = Math.max(max, countCells(matrix, i, j));
            }
        }
        return max;
    }
    
    private static int countCells(int[][] matrix, int i, int j) {
        if (i < 0 || j < 0 || i >= matrix.length || j >= matrix[0].length) return 0;
        if (matrix[i][j] == 0) return 0;
        int count = matrix[i][j]--;
        count += countCells(matrix, i + 1, j);
        count += countCells(matrix, i - 1, j);
        count += countCells(matrix, i, j + 1);
        count += countCells(matrix, i, j - 1);
        count += countCells(matrix, i + 1, j + 1);
        count += countCells(matrix, i - 1, j - 1);
        count += countCells(matrix, i - 1, j + 1);
        count += countCells(matrix, i + 1, j - 1);
        return count;
    }