aoc2017day02

import sys

def doit(input):
    rows = input.strip().split("\n")
    sum = 0
    for r in rows:
        vals = list(map(int,r.strip().split()))
        min = 2**32
        max = 0
        for v in vals:
            if v < min: min = v
            if v > max: max = v
        diff = max - min
        sum += diff
    return "%d" % sum

input = sys.stdin.read()
print(doit(input))