package main

import (
	"fmt"
	"io/ioutil"
	"log"
	"strconv"
	"strings"
)

const (
	MaxDays     = 256
	PartOneDays = 80
	MaxTimer    = 8
)

func shiftArrayLeft(arr *[MaxTimer + 1]int64) {
	for i := 1; i < len(arr)-1; i++ {
		arr[i-1] = arr[i]
		arr[i] = arr[i+1]
	}
}

func calcSum(arr *[MaxTimer + 1]int64) (sum int64) {
	for _, v := range arr {
		sum += v
	}
	return
}

func main() {
	file, err := ioutil.ReadFile("input.txt")
	if err != nil {
		log.Fatal(err)
	}
	inputStrs := strings.Split(strings.Trim(string(file), "\n"), ",")

	var dayCounts [MaxTimer + 1]int64
	for _, v := range inputStrs {
		num, _ := strconv.Atoi(v)
		dayCounts[num]++
	}

	for daysPassed := 0; daysPassed < MaxDays; daysPassed++ {
		if daysPassed == PartOneDays {
			fmt.Println(calcSum(&dayCounts))
		}

		newSpawn := dayCounts[0]
		shiftArrayLeft(&dayCounts)
		dayCounts[6] += newSpawn
		dayCounts[8] = newSpawn
	}

	fmt.Println(calcSum(&dayCounts))
}