1 #include<stdio.h>
2 #include<string.h>
3 int a[105][105];
4 int main()
5 {
6 int n,i,j,t;
7 while(~scanf("%d",&n))
8 {
9 memset(a,0,sizeof a);
10 t=a[i=0][j=n-1]=1;
11 while(t<n*n)
12 {
13 while(i+1<n && !a[i+1][j]) a[++i][j]=++t;
14 while(j-1>=0 && !a[i][j-1]) a[i][--j]=++t;
15 while(i-1>=0 && !a[i-1][j]) a[--i][j]=++t;
16 while(j+1<n && !a[i][j+1]) a[i][++j]=++t;
17 }
18 for(i=0; i<n; ++i)
19 {
20 for(j=0; j<n; ++j)
21 if(j)
22 printf(" %d",a[i][j]);
23 else
24 printf("%d",a[i][j]);
25 printf("\n");
26 }
27 }
28 }
