"strings"

	d, err := parseInput("input.test")

	d, err := parseInput("input.txt")

	// big := genBig(d)
	// log.Println(solveFirst(big))

}
func genBig(d distance) distance {
	const expansion = 5
	bigd := make(distance, expansion*len(d))
	for i := range bigd {
		bigd[i] = make([]int, expansion*len(d[0]))
	}
	for y := range d {
		for x := range d[y] {
			for j := 0; j < expansion; j++ {
				for i := 0; i < expansion; i++ {
					bigd[y+j*len(d)][x+i*len(d[0])] = (d[y][x]+i+j)%10 + (d[y][x]+i+j)/10
				}
			}
		}
	}
	return bigd

func (d distance) String() string {
	ret := strings.Builder{}
	ret.WriteByte('\n')
	for _, row := range d {
		for _, ch := range row {
			ret.WriteString(strconv.Itoa(ch))
		}
		ret.WriteByte('\n')
	}
	return ret.String()
}