Telescopic Matrix

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

/**
 * Created by ChaosFire on 29.12.2017 г.
 */
public class TelescopicMatrix {

    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        int size = Integer.parseInt(reader.readLine());
        int[][] matrix = readMatrix(size, reader);
        reader.close();
        System.out.println(isTelescopic(matrix, size));
    }

    private static boolean isTelescopic(int[][] matrix, int size) {
        int value = 1;//layer value
        int layerCount = size / 2;//layer count, center, if it exists, is not included as a layer
        for (int i = 0; i < layerCount; i++) {
            int x = i;
            int y = i;
            while (y < size - 1 - i) {//go right
                if (matrix[x][y] != value) {
                    return false;
                }
                y++;
            }
            while (x < size - 1 - i) {//go down
                if (matrix[x][y] != value) {
                    return false;
                }
                x++;
            }
            while (y > i) {//go left
                if (matrix[x][y] != value) {
                    return false;
                }
                y--;
            }
            while (x > i) {//go up
                if (matrix[x][y] != value) {
                    return false;
                }
                x--;
            }
            value++;
        }
        return size % 2 == 0 || matrix[layerCount][layerCount] == value;//check center, if there is such, and return answer
    }

    private static int[][] readMatrix(int size, BufferedReader reader) throws IOException {
        int[][] matrix = new int[size][size];
        for (int i = 0; i < size; i++) {
            String[] row = reader.readLine().split("\\s+");
            for (int j = 0; j < size; j++) {
                matrix[i][j] = Integer.parseInt(row[j]);
            }
        }
        return matrix;
    }
}