#/usr/bin/env python


total_prio = 0
with open("input.txt", "r") as f:
    i = 0
    c = set()
    for line in f:
        line = line.strip()
        i += 1
        if i == 1:
            c = set(line)
            continue
        c = c.intersection(set(line))
        if i < 3:
            continue
        i = 0
        c = ord(list(c)[0])
        if c >= 97:
            total_prio += c - 96
        else:
            total_prio += c - 38
            
print(total_prio)