with open("input3.txt") as f:
    a = dict(zip(map(chr,(list(range(97,123))+list(range(65,91)))),range(1,53)))
    s = 0
    for line in f.readlines():
        line = line.strip()
        d, f = map(set,(line[:len(line)//2],line[len(line)//2:]))
        s += a[(d&f).pop()]
    print(s)