#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>

int main(){
    int n = 26;
    int *h = malloc(sizeof(int) * n);
    for(int h_i = 0; h_i < n; h_i++){
       scanf("%d",&h[h_i]);
    }
    char* word = (char *)malloc(512000 * sizeof(char));
    scanf("%s",word);
    int maximum = 1;
    for(long int i = 0 ;i< strlen(word);i++){
        if(h[word[i]-'a'] > maximum)
            maximum = h[word[i]-'a'];
    }
    printf("%ld",strlen(word)*maximum);
    return 0;
}