from string import ascii_letters

sum_of_priorities = 0

def get_3_rucksacks(fh):
    return [next(fh).strip() for _ in range(3)]


with open("3.in") as fh:
    while True:
        try:
            rucksacks = get_3_rucksacks(fh)
        except StopIteration:
            break

        a, b, c = rucksacks

        item_in_all = list(set(a).intersection(set(b)).intersection(set(c)))[0]

        priority = ascii_letters.find(item_in_all) + 1
        sum_of_priorities += priority

print(sum_of_priorities)