def priority(item):
    if item < 'a':
        # uppercase
        return ord(item)-38
    else:
        # lowercase
        return ord(item)-96

totaal = 0
with open("input.txt", "r") as f:
    for line in f.readlines():
        line = line.strip("\n")
        h = int(len(line)/2)
        left = line[:h]
        right = line[h:]
        for c in left:
            if c in right:
                totaal += priority(c)
                print(c)
                break
print(totaal)