import sys
import numpy as np
import pprint, string
arr = []
alpha=list(string.ascii_letters)
values=[]
with open(sys.argv[1]) as f:
	for l in f:
		line=l.split()[0]
		first, second = line[:len(line)//2],line[len(line)//2:]
		shared=list(set(first)&set(second))[0]
		index=alpha.index(shared)+1
		values.append(index)
		arr.append([first,second,shared,int(index)])
		

#pprint.pprint(arr)
print(sum(values))