<?php
function shift_calc($x, $y) {
return $x != '0' ? $x : $y;
};
function shift_sum($am, $pm) {
};
$result = shift_sum('A00A00A', '0P000P0');
PD9waHAKCmZ1bmN0aW9uIHNoaWZ0X2NhbGMoJHgsICR5KSB7CiAgICByZXR1cm4gJHggIT0gJzAnID8gJHggOiAkeTsKfTsKCmZ1bmN0aW9uIHNoaWZ0X3N1bSgkYW0sICRwbSkgewogICAgcmV0dXJuIGltcGxvZGUoYXJyYXlfbWFwKCdzaGlmdF9jYWxjJywgc3RyX3NwbGl0KCRhbSksIHN0cl9zcGxpdCgkcG0pKSk7Cn07CgokcmVzdWx0ID0gc2hpZnRfc3VtKCdBMDBBMDBBJywgJzBQMDAwUDAnKTsKCnZhcl9kdW1wKCRyZXN1bHQpOw==