#!/usr/bin/python

import sys
from collections import defaultdict

with open("input01.txt","r") as f:
    data = [int(i) for i in f.readline().split(',')]

count = defaultdict(int)
for i in data:
	count[i] += 1

pos_min = min([i for i in count.keys()])
pos_max = max([i for i in count.keys()])

results = []

for pos in range(pos_min, pos_max+1):
	tmp = 0
	for i in count.keys():
		a=abs(pos-i)
		tmp += a*(a+1)/2*count[i] 
	results.append(tmp)
print(min(results))