Difficult star pattern in #c

I am trying to solve the above pattern in c in order to create a square into the center of a bigger square.

By far i can only make the big square. p.e. :input=6

******
*    *
* ** *
* ** * 
*    *
****** 

int main(int argc, char *argv[]) {
    int i,j,n;

    scanf("%d",&n);
    //FIRST LINE
    for(i = 0; i < n; i++)
   {
       printf("*");
   }
   printf("\n");

   for(i = 1; i <n-1; i++)
   {
       printf("*");
       for(j = 1; j <n-1; j++)
       {
          printf(" ");
       }  
       printf("*");
       printf("\n");
   }

   //lAST LINE

   for(i = 0; i < n; i++)
   {
       printf("*");
   }
   printf("\n");
    return 0;
}