Python, trying to be readable....

data = open('input.txt','r').read().rstrip().split()

def priority(c):
    offset = 96 if c.islower() else 38
    return ord(c)-offset

part_1 = 0
for ruck in data:
    ru, ck = ruck[:len(ruck)//2], ruck[len(ruck)//2:]
    for item in (set(ru) & set(ck)):
        part_1 += priority(item)

part_2 = 0
for i in range(0,len(data),3):
    ruak, rubk, ruck = set(data[i]), set(data[i+1]), set(data[i+2])
    for item in (ruak & rubk & ruck):
        part_2 += priority(item)

print(part_1, part_2)