#!/bin/python3
import sys,re
from collections import Counter
from pprint import pprint
sys.path.insert(0, '../../')
from fred import list2int,get_re,nprint,lprint

input_f = 'input'

part = 2

def loadList(input_f):
    left = []
    right = []
    
    with open(input_f) as file:
        for line in file:
            l = line.rstrip().split()
            left.append(int(l[0]))
            right.append(int(l[1]))
    return left,right


#########################################
#                                       #
#              Part 1                   #
#                                       #
#########################################
if part == 1:
    sum = 0
    left,right = loadList(input_f)
    for i in range(len(left)):
        sum += abs((left.pop(left.index(min(left)))-right.pop(right.index(min(right)))))
    print(sum)

    
#########################################
#                                       #
#              Part 2                   #
#                                       #
#########################################
if part == 2:
    sim = 0
    left,right = loadList(input_f)
    right = Counter(right)
    for i in range(len(left)):
      sim += (left[i] * right[left[i]])
    print(sim)