<?php
$ads1="<div style=\"float:right;width:100px;height:100px;\"><s trong>AAA</strong></div>";
$ads2="<div style=\"float:left;width:100px;height:100px;\"><st rong>BBB</strong></div>";
$ads3="<div style=\"float:right;width:100px;height:100px;\"><s trong>CCC</strong></div>";
$xsize=400;
$article=$post->post_content;
// $article=apply_filters('the_content', $post->post_content);
$size1=(int)(strlen($article)/2);
$size2=strlen($article)-(int)(strlen($article)/2)-$xsize;
$size3=strlen($article)-$xsize;
$size4=$xsize;
$article1=substr($article, 0, $size1);
$article2=substr($article, $size1, $size2);
$article3=substr($article, $size3, $size4);
echo $ads1.$article1.$ads2.$article2.$ads3.$article3;
?>