Digits

using System;
using System.Linq;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            int[,] matrix = new int[n, n];
            FillMatrix(matrix, n);
            int sum = 0;

            for (int i = 0; i < n; i++)
            {
                for (int j = 0; j < n; j++)
                {
                    sum += CheckForOne(matrix, i, j);
                    //CheckForTwo(matrix, sum, i, j);
                    //CheckForThree(matrix, sum, i, j);
                    //CheckForFour(matrix, sum, i, j);
                    //CheckForFive(matrix, sum, i, j);
                    //CheckForSix(matrix, sum, i, j);
                    //CheckForSeven(matrix, sum, i, j);
                    //CheckForEight(matrix, sum, i, j);
                    //CheckForNine(matrix, sum, i, j);
                }
            }
            Console.WriteLine(sum);

        }

        private static int CheckForOne(int[,] matrix, int i, int j)
        {
            int sum = 0;
            if (i - 2 < 0 || j + 2 >= matrix.GetLength(1) || i + 2 >= matrix.GetLength(0))
            {
                return sum;
            }
            bool checkOne = matrix[i, j] == matrix[i - 1, j + 1] && matrix[i, j] == matrix[i - 2, j + 2] &&
                matrix[i, j] == matrix[i - 1, j + 2] && matrix[i, j] == matrix[i, j + 2] && matrix[i, j] == matrix[i + 1, j + 2] &&
                matrix[i, j] == matrix[i + 2, j + 2];
            if (checkOne)
            {
                sum++;
            }
            return sum;
        }

        private static void FillMatrix(int[,] matrix, int n)
        {
            for (int i = 0; i < n; i++)
            {
                int[] numsLine = Console.ReadLine().Split().Select(int.Parse).ToArray();
                for (int j = 0; j < n; j++)
                {
                    matrix[i, j] = numsLine[j];
                }
            }
        }
    }
}