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))