import argparse
import functools

parser = argparse.ArgumentParser()
parser.add_argument("ifile", type=argparse.FileType('r'))
args = parser.parse_args()
crabs = [int(x) for x in args.ifile.readline().split(',')]

print(min([sum([abs(start - pos) for start in crabs]) for pos in range(0, len(crabs) + 1)]))