usort($crew_city, function ($v1, $v2) {
return strcmp($v1, $v2);
});
$letter = null;
$i = 0;
foreach ($crew_city as $v) {
$currentLetter = mb_substr($v, 0, 1, 'utf-8');
if ($currentLetter !== $letter) {
$letter = $currentLetter;
echo "<span class='clr86CA43'>$letter</span><br>", PHP_EOL;
}
echo $crew[$i], PHP_EOL;
$i++;
}