char buffer[27];

#ifdef reverse
#define cpy(s1,s2,n) copy(s2,s1,n)
#else
#define cpy copy
#endif

main()
{
  cpy("abcdefghijklmnopqrstuvwxyz", buffer, 27);
  if (strcmp(buffer, "abcdefghijklmnopqrstuvwxyz") != 0) exit(1);
  cpy(buffer, buffer+3, 26-3);
  if (strcmp(buffer, "abcabcdefghijklmnopqrstuvw") != 0) exit(1);
  cpy("abcdefghijklmnopqrstuvwxyz", buffer, 27);
  cpy(buffer+3, buffer, 26-3);
  if (strcmp(buffer, "defghijklmnopqrstuvwxyzxyz") != 0) exit(1);
  exit(0);
}