package main

import (
	"fmt"
	"os"
	"sort"
	"strconv"
	"strings"
)

func main() {

	lines := parse()

	// var first = 0
	// var last = 0

	var left = []int{}
	var right = []int{}

	for _, line := range lines {
		fmt.Println(line)

		if line == "" {
			continue
		}

		nums := strings.Fields(line)

		fmt.Println(nums[0], nums[1])
		l, _ := strconv.Atoi(nums[0])
		r, _ := strconv.Atoi(nums[1])
		left = append(left, l)
		right = append(right, r)

		// for i := 0; i < len(line); i++ {
		// 	//fmt.Println(int(line[i]))
		// 	x, err := strconv.Atoi(string(line[i]))
		// 	if err == nil {
		// 		last = x
		// 		break
		// 	}
		// }
	}

	sort.Ints(left)
	sort.Ints(right)

	var sum = 0

	for i := 0; i < len(left); i++ {
		var diff = right[i] - left[i]
		if diff < 0 {
			diff *= -1
		}
		sum += diff
	}

	fmt.Println(sum)

}

func parse() []string {
	filePath := os.Args[1]
	data, _ := os.ReadFile(filePath)
	chunks := strings.Split(string(data), "\n")
	return chunks
}