<?php
fscanf(STDIN, "%d", $n);
$As = explode(' ', fgets(STDIN));
$Bs = explode(' ', fgets(STDIN));
$Cs = explode(' ', fgets(STDIN));
$total = array_sum($Bs);
for($i=0; $i<$n; $i++){
	if($As[$i+1]-$As[$i]==1){
    	$total += $Cs[$i-1];
    }
};
echo $total;