#!/usr/bin/env python3

list1 = [];
list2 = [];
with open("input.txt") as file:
 for line in file:
  if line.strip():
   num1,num2 = map(int, line.split())
   list1.append(num1)
   list2.append(num2)

slist1 = sorted(list1);
slist2 = sorted(list2);

result = 0;
for index in range(len(slist1)):
 result+=abs(slist1[index]-slist2[index])

print(f'Result: {result}')