byte *dir = stk_printf("solutions/%s/%s", user, task);
byte *name = stk_printf("%s/%s.%s", dir, part, ext);
if (unlink(name) < 0)
byte *dir = stk_printf("solutions/%s/%s", user, task);
byte *name = stk_printf("%s/%s.%s", dir, part, ext);
if (unlink(name) < 0)