<?php
$html = '';
$blocks = 10;
for($i = 1; $i <= $blocks; ++$i) {
if($i % 2 == 0) {
$html .= '</div>' . PHP_EOL;
}
else {
$html .= '<div class="wrap">
<div class="block"></div>
<div class="block"></div>' . PHP_EOL;
}
}
echo $html;
PD9waHAKCiRodG1sID0gJyc7CiRibG9ja3MgPSAxMDsKZm9yKCRpID0gMTsgJGkgPD0gJGJsb2NrczsgKyskaSkgewoJaWYoJGkgJSAyID09IDApIHsKCQkkaHRtbCAuPSAnPC9kaXY+JyAuIFBIUF9FT0w7Cgl9CgllbHNlIHsKCQkkaHRtbCAuPSAnPGRpdiBjbGFzcz0id3JhcCI+CiAgIDxkaXYgY2xhc3M9ImJsb2NrIj48L2Rpdj4KICAgPGRpdiBjbGFzcz0iYmxvY2siPjwvZGl2PicgLiBQSFBfRU9MOwoJfQp9CgplY2hvICRodG1sOw==