// https://omegaup.com/arena/problem/Dibujando-un-tache 
#include <stdio.h> 
 
int main( ) { 
   int n; 
   scanf("%d", &n); 
 
   for (int k = 1; k <= n; ++k) { 
      for (int i = 1; i <= n; ++i) { 
         if (k == i || i == n - (k - 1)) { 
            printf("@"); 
         } else { 
            printf(" "); 
         } 
      } 
      printf("\n"); 
   } 
}