<?php
$a[] = explode(" ",trim(fgets(STDIN)));

sort($a);

if ($a[1]-$a[0] == 4 && $a[1] >= 8) {
    echo $a[0]+4;
}elseif ($a[1]-$a[0] == 4 && $a[1] <= 7) {
    echo $a[1]+4;
}elseif ($a[1]-$a[0] == 8) {
    echo $a[0]+4;
}


?>