printf (" max_height %d\n", ao_max_height);
printf (" avg_height %d\n", ao_avg_height);
printf (" error_h %d\n", ao_error_h);
printf (" max_height %d\n", ao_max_height);
printf (" avg_height %d\n", ao_avg_height);
printf (" error_h %d\n", ao_error_h);