input = open("./input.txt", "r")

def determinePriority(item):
    if (item.isupper()):
        return priorityValue[item.lower()] + 26
    return priorityValue[item]

total = 0

priorityValue = {
    "a": 1,
    "b": 2,
    "c": 3,
    "d": 4,
    "e": 5,
    "f": 6,
    "g": 7,
    "h": 8,
    "i": 9,
    "j": 10,
    "k": 11,
    "l": 12,
    "m": 13,
    "n": 14,
    "o": 15,
    "p": 16,
    "q": 17,
    "r": 18,
    "s": 19,
    "t": 20,
    "u": 21,
    "v": 22,
    "w": 23,
    "x": 24,
    "y": 25,
    "z": 26
}

for line in input:
    lineLength = len(line) - 1
    lineLength = int(lineLength / 2)
    pack1 = line[:lineLength]
    pack2 = line[lineLength:]
    dupItem = ""
    for item in pack1:
        if (pack2.__contains__(item)):
            dupItem = item
            break
    total += determinePriority(dupItem)

print(total)