package main

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

func configure(scanner *bufio.Scanner) {
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 1000005), 1000005)
}
func getNextString(scanner *bufio.Scanner) string {
	scanned := scanner.Scan()
	if !scanned {
		panic("scan failed")
	}
	return scanner.Text()
}
func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}
func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}
func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}
func main() {
	fp := os.Stdin
	wfp := os.Stdout
	extra := 0
	if os.Getenv("I") == "IronMan" {
		fp, _ = os.Open(os.Getenv("END_GAME"))
		extra = 100
	}
	scanner := bufio.NewScanner(fp)
	configure(scanner)
	writer := bufio.NewWriter(wfp)
	defer func() {
		r := recover()
		if r != nil {
			fmt.Fprintln(writer, r)
		}
		writer.Flush()
	}()
	solve(scanner, writer)
	for i := 0; i < extra; i++ {
		fmt.Fprintln(writer, "-----------------------------------")
		solve(scanner, writer)
	}
}
func solve(scanner *bufio.Scanner, writer *bufio.Writer) {
	h := getNextInt(scanner)
	w := getNextInt(scanner)
	g := make(grid, h)
	for i := 0; i < h; i++ {
		g[i] = getNextString(scanner)
	}
	var ans float64
	ans = math.MaxFloat64
	for i := 0; i < w; i++ {
		a := g.paint(0, i+1)
		if ans > a {
			ans = a
		}
	}
	for i := 0; i < w; i++ {
		a := g.paint(h+1, i+1)
		if ans > a {
			ans = a
		}
	}
	for i := 0; i < h; i++ {
		a := g.paint(i+1, 0)
		if ans > a {
			ans = a
		}
	}
	for i := 0; i < h; i++ {
		a := g.paint(i+1, w+1)
		if ans > a {
			ans = a
		}
	}
	fmt.Fprintln(writer, ans)
}

type grid []string

func (g grid) paint(y, x int) float64 {
	h := len(g)
	w := len(g[0])
	var ans float64
	for i := 0; i < h; i++ {
		for j := 0; j < w; j++ {
			if g[i][j] == '0' {
				continue
			}
			ans += math.Sqrt(math.Pow(float64(i+1-y), 2) + math.Pow(float64(j+1-x), 2))
		}
	}
	return ans
}