package main

import (
	"bufio"
	"fmt"
	"log"
	"os"
)

func main() {
	file, err := os.Open("input.txt")
	if err != nil {
		log.Fatal(err)
	}
	defer file.Close()

	scanner := bufio.NewScanner(file)
	scanner.Split(bufio.ScanLines)

	insertions := make(map[string]string)
	pairs := make(map[string]uint64)

	var i int
	var template string
	for scanner.Scan() {
		line := scanner.Text()
		if line == "" {
			continue
		}
		if i == 0 {
			template = line
			for j := 0; j < len(template)-1; j++ {
				pairs[string(template[j])+string(template[j+1])]++
			}
		} else {
			var one, two, three rune
			fmt.Sscanf(line, "%c%c -> %c", &one, &two, &three)
			insertions[string(one)+string(two)] = string(three)
		}
		i++
	}

	var newPairs map[string]uint64

	for j := 0; j < 40; j++ {
		newPairs = make(map[string]uint64)
		for pair, count := range pairs {
			firstNewPair := string(pair[0]) + insertions[pair]
			secondNewPair := insertions[pair] + string(pair[1])
			newPairs[firstNewPair] += uint64(count)
			newPairs[secondNewPair] += uint64(count)
		}
		pairs = newPairs
		if j == 9 {
			fmt.Println(count(&pairs))
		}
	}
	fmt.Println(count(&pairs))
}

func count(pairs *map[string]uint64) uint64 {
	counts := make(map[string]uint64)
	for pair, count := range *pairs {
		counts[string(pair[1])] += uint64(count)
	}

	var maxCount, minCount uint64 = 0, 0xffffffffffffffff

	for _, total := range counts {
		if total > maxCount {
			maxCount = total
		}
		if total < minCount {
			minCount = total
		}
	}

	return maxCount - minCount
}