View difference between Paste ID: Ap7PAMm4 and HFjwXXZQ

 public static void main(String[] args) throws IOException {
         BufferedReader rd = new BufferedReader(new InputStreamReader(System.in));
 
         int[][] matrix = readMatrix(rd);
         int[][] bestM = new int[3][3];
         int max = 0;
 
         for (int i = 0; i < matrix.length - 2; i++) {
             for (int j = 0; j < matrix[i].length - 2; j++) {
 
                 int[][] mat = getNewMatrix(matrix, i, j);
                 int sum = getSum(mat);
 
                 if (sum > max) {
                     max = sum;
                     bestM = mat;
                 }
             }
         }
 
         System.out.println("Sum = " + max);
         printMatrix(bestM);
     }
 
     private static int getSum(int[][] mat) {
         int sum = 0;
         for (int[] ints : mat)
             sum += Arrays.stream(ints).sum();
         return sum;
     }
 
     private static int[][] getNewMatrix(int[][] matrix, int i, int j) {
         int[][] mat = new int[3][3];
         for (int k = 0; k < 3; k++)
             mat[k] = Arrays.copyOfRange(matrix[i + k], j, j + 3);
         return mat;
     }
 
     private static void printMatrix(int[][] ar) {
         for (int[] nums : ar)
             System.out.println(Arrays.toString(nums).replaceAll("[\\[\\],]", ""));
     }
 
     private static int[][] readMatrix(BufferedReader rd) throws IOException {
         int[] size = Arrays.stream(rd.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
         int[][] mat = new int[size[0]][size[1]];
         for (int i = 0; i < mat.length; i++)
             mat[i] = Arrays.stream(rd.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
         return mat;
     }