with open("day3\input.txt") as f:
    data = f.readlines()

def findCommon(leftside:str,rightside:str):
    for char in leftside:
        if char in rightside:
            return ord(char)

sum  = 0
line:str
for line in data:
    size = int(len(line)/2)
    leftside = line[:size]
    rightside = line[size:]
    common_letter_ascii = findCommon(leftside,rightside)
    if common_letter_ascii >= 97:
        priority = common_letter_ascii - 96
    else:
        priority = common_letter_ascii - 64 + 26
    sum  +=  priority
print(sum)