package main

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

func getPacks(filename string) []int {
    var packs []int

    // read sample data
    file, err := os.Open(filename)
    if err != nil {
        fmt.Println(err.Error())
        return packs
    }

    // close file read at the end of all calculations
    defer file.Close()

    var line string
    var amount int

    var sum int

    // create buffer scanner for file
    scanner := bufio.NewScanner(file)
    for scanner.Scan() {
        // read by file
        line = scanner.Text()

        // create pack of amounts separated by empty line
        if line == "" {
            packs = append(packs, sum)
            sum = 0

        } else {
            // calculate summ
            amount, err = strconv.Atoi(line)
            if err != nil {
                panic(err)
            }

            sum += amount
        }
    }

    return packs
}

func getMaxPacks(packs []int) (maxPack int, last3Sum int) {
    // sort packs by ascending order
    sort.Ints(packs[:])
    // get largest 3 packs
    last3 := packs[len(packs)-3:]

    // get last (largest) pack
    // 66487
    maxPack = packs[len(packs)-1]

    for _, amount := range last3 {
        // calculate the sum of 3 largest amounts
        // 197301
        last3Sum += amount
    }

    return maxPack, last3Sum
}

func main() {
    // os.Arg[1] should be used for execution a binary
    // os.Arg[2] only for `go run`
    filename := os.Args[2]
    
    packs := getPacks(filename)
    maxPack, last3Sum := getMaxPacks(packs)

    fmt.Println(maxPack, last3Sum)
}