<?php
$yukiHotel = trim(fgets(STDIN));
$insteadHotel = trim(fgets(STDIN));
$count = trim(fgets(STDIN));
$number = array();
for ($i = 0; $i < $count; $i++) {
    $number[] = trim(fgets(STDIN));
}
$double = array_count_values($number);
$ans = 0;
foreach ($double as $value){
    if ($value > 1) {
        $doubleCount = $value -1;
        $ans += ($doubleCount * ($yukiHotel + $insteadHotel));
    } else {
        $ans = 0;
    }
}
echo $ans;