object Solution {

    def main(args: Array[String]) {
        val sc = new java.util.Scanner (System.in);
        var h = new Array[Int](26);
        for(h_i <- 0 to 25) {
           h(h_i) = sc.nextInt();
        }
        var word = sc.next();
        val charHeights: Map[Char,Int] = ('a' to 'z').zip( h ).toMap
        val maxHeight = word.toLowerCase().toList.map{ c => charHeights(c) }.max
        println( maxHeight * word.length )
    }
}