#/usr/bin/env python


total_prio = 0
with open("input.txt", "r") as f:
    for line in f:
        l2 = int(len(line.strip())/2)
        c1 = set(line[:l2])
        c2 = set(line[l2:])        
        c = c1.intersection(c2)
        
        c = ord(list(c)[0])
        if c >= 97:
            total_prio += c - 96
        else:
            total_prio += c - 38
            
print(total_prio)