#!/usr/bin/python3
import fileinput

priority = {}
p = 1
for c in 'abcdefghijklmnopqrstuvwxyz':
	priority[c] = p
	p += 1
for c in 'ABCDEFGHIJKLMNOPQRSTUVWXYZ':
	priority[c] = p
	p += 1

total = 0
for line in fileinput.input():
	line = line.rstrip()
	n = len(line)
	first = set(list(line[0:int(n/2)]))
	second = set(list(line[int(n/2):]))
	inter = first & second
	total += priority[inter.pop()]

print(total)