step3.php

#!/usr/bin/php
<?php
fclose(STDOUT); $STDOUT = fopen('F1.csv', 'w');

define('d',";");
define('n',"\n");

$f_=file('F1_.csv',FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);

$szurj=array();
foreach($f_ as $i=>$f){
        if ($i==0) continue;
        $x=explode(d,$f);
        if ( empty($szurj[$x[0].d.$x[3].d.$x[6].d.$x[8]]))      $szurj[$x[0].d.$x[3].d.$x[6].d.$x[8]]=$x[7];
        else { if ($szurj[$x[0].d.$x[3].d.$x[6].d.$x[8]]<$x[7]) $szurj[$x[0].d.$x[3].d.$x[6].d.$x[8]]=$x[7];}
}

foreach($f_ as $i=>$f){
        if ($i==0) {print $f.n; continue;}
        $x=explode(d,$f);
        if (empty($szurj[$x[0].d.$x[3].d.$x[6].d.$x[8]])) continue;
        if ($szurj[$x[0].d.$x[3].d.$x[6].d.$x[8]]!=$x[7]) continue;
        print implode(d,$x).n;
}