lines = [i for i in open("input.txt", 'r').read().splitlines()]

letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
sum = 0

for l in lines:
    found = False
    for c in l[:int(len(l)/2)]:
        for d in l[int(len(l)/2):]:
            if c == d:
                if not found:
                    sum += letters.index(c)+1
                    found = True

print(sum)