using System;
using System.Collections.Generic;
class PrintMatrixSizeNFour
{
    static int N = 0;
    static void Main()
    {
        Console.Write("Size of the matrix [N,N] = ");
        N = int.Parse(Console.ReadLine());
        int[,] matrix = new int[N, N];
        int loops = 0;
        int numberOfOperations = (N - 1) * 2 + 1;
        Console.WriteLine();

        while (loops <= numberOfOperations)
        {
            FirstSide(matrix);
            loops++;
            if (loops == numberOfOperations)
            {
                break;
            }

            SecondSide(matrix);
            loops++;
            if (loops == numberOfOperations)
            {
                break;
            }

            ThirdSide(matrix);
            loops++;
            if (loops == numberOfOperations)
            {
                break;
            }

            FourthSide(matrix);
            loops++;
        }
        PrintMatrix(matrix);
        Console.WriteLine();
    }


    static int firstSideModifi = 0;
    static int num = 1;
    static int secondSideModifi = 0;
    static int thirdSideModifi = 0;
    static int fourthSideModifi = 0;

    static int[,] FirstSide(int[,] matrix)
    {
        for (int p = firstSideModifi; p <= firstSideModifi; p++)
        {
            for (int i = firstSideModifi; i < matrix.GetLength(0) - firstSideModifi; i++)
            {
                matrix[i, p] = num;
                num++;
            }
        }
        firstSideModifi++;
        return matrix;
    }

    static int[,] SecondSide(int[,] matrix)
    {
        for (int i = (N - 1) - secondSideModifi; i <= (N - 1) - secondSideModifi; i++)
        {
            for (int p = 1 + secondSideModifi; p < N - secondSideModifi; p++)
            {
                matrix[i, p] = num;
                num++;
            }
        }
        secondSideModifi++;
        return matrix;
    }

    static int[,] ThirdSide(int[,] matrix)
    {
        for (int p = (N - 1) - thirdSideModifi; p <= (N - 1) - thirdSideModifi; p++)
        {
            for (int i = (N - 2) - thirdSideModifi; i >= thirdSideModifi; i--)
            {
                matrix[i, p] = num;
                num++;
            }
        }
        thirdSideModifi++;
        return matrix;
    }

    static int[,] FourthSide(int[,] matrix)
    {
        for (int i = 0 + fourthSideModifi; i <= fourthSideModifi; i++)
        {
            for (int p = (N - 2) - fourthSideModifi; p >= 1 + fourthSideModifi; p--)
            {
                matrix[i, p] = num;
                num++;
            }
        }
        fourthSideModifi++;
        return matrix;
    }

    static void PrintMatrix(int[,] matrix)
    {
        for (int i = 0; i < matrix.GetLength(0); i++)
        {
            for (int p = 0; p < matrix.GetLength(1); p++)
            {
                Console.Write("{0, 5} ", matrix[i, p]);
            }
            Console.WriteLine();
        }
    }
}