package main

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

// Returns 0 if we find the end of the path, '.' or '#' otherwise
func getCoords(s []string, x, y int) rune {
	length := len(s)
	if y+1 >= length {
		return 0
	}
	width := len(s[y])
	if y < 0 || x < 0 { // off the map = no tree
		return '.'
	}
	return rune(s[y][x%width])

}

func main() {
	d, _ := ioutil.ReadFile("in3.txt")
	text := string(d)
	lines := strings.Split(text, "\n")
	paths := [][]int{
		{1, 1}, // {right,down}
		{3, 1},
		{5, 1},
		{7, 1},
		{1, 2},
	}
	total := 1 // this will have all the paths multiplied into it
	for _, p := range paths {
		x := 0
		y := 0 // start in the top-left corner
		trees := 0
		for {
			t := getCoords(lines, x, y)
            done := false
			switch t {
			case 0:
                done = true
			case '#':
				trees += 1
			}
            if done == true {
                break
            }
			//fmt.Printf("in3.txt:%d:%d: %#v\n", y+1, (x%len(lines[y]))+1, tree)
			x += p[0]
			y += p[1]
		}
		total = total * trees
	}
	fmt.Println(total)
}