package main

import (
	"fmt"
	"math"
	"os"
	"slices"
	"strconv"
	"strings"
)

func check(e error) {
    if e != nil {
        panic(e)
    }
}

func sumArray(list []int) int {
	result := 0
	for _, item := range list{
		result += item
	}
	return result
}

func main() {
	data, err := os.ReadFile("./input.txt")
	check(err)
	//fmt.Println(string(data))
	dataRows := strings.Split(string(data), "\r\n")
	var leftList []int
	var rightList []int
	var diffList []int
	//fmt.Println(dataRows)
	for _, row := range dataRows {
		l, _ := strconv.Atoi(strings.Split(row, "   ")[0])
		r, _ := strconv.Atoi(strings.Split(row, "   ")[1])
		leftList = append(leftList, l)
		rightList = append(rightList, r)
	}
	//fmt.Println(rightList)
	slices.Sort(leftList)
	slices.Sort(rightList)
	//fmt.Println(leftList)
	//fmt.Println(rightList)
	for idx, l := range leftList {
		diffList = append(diffList, int(math.Abs(float64(rightList[idx] - l))))
	}
	//fmt.Println(diffList)
	fmt.Println(sumArray(diffList))
}