smartOJ[NOIP1995P3]
import java.util.*;
public class Main
{
public static void main(String[] args) {
String str =null;
Scanner scanner = new Scanner(System.in);
int n = scanner.nextInt();
int[][] numbers = new int[n][n];
boolean[][] isE = new boolean[n][n];
int x=0,y=n-1,k=1;
numbers[x][y]=k++;
isE[x][y] = true;
while(k<= n*n){
while(x<n-1 && !isE[x+1][y]){
x++;
numbers[x][y]=k++;
isE[x][y] = true;
}
while(y>0 && !isE[x][y-1]){
y--;
numbers[x][y]=k++;
isE[x][y] = true;
}
while(x>0 && !isE[x-1][y]){
x--;
numbers[x][y]=k++;
isE[x][y] = true;
}
while(y<n-1 && !isE[x][y+1]){
y++;
numbers[x][y]=k++;
isE[x][y] = true;
}
}
//格式输出
if(n<4){
for(int i=0;i<n;i++){
for(int j=0; j<n; j++){
System.out.printf("%d ",numbers[i][j]);
}
System.out.println();
}
} else if(n<10){
for(int i=0;i<n;i++){
for(int j=0; j<n; j++){
System.out.printf("%2d ",numbers[i][j]);
}
System.out.println();
}
} else if(n==10){
for(int i=0;i<n;i++){
for(int j=0; j<n; j++){
System.out.printf("%3d ",numbers[i][j]);
}
System.out.println();
}
}
}
}