using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
//using System.Text;
//using System.Text.RegularExpressions;
//using System.Globalization;
//using System.Diagnostics;
using static System.Console;
//using System.Numerics;
using static System.Math;
//using pair = Pair<int, int>;

class Program
{
    static void Main()
    {
        //SetOut(new StreamWriter(OpenStandardOutput()) { AutoFlush = false });
        new Program().solve();
        Out.Flush();
    }
    Scanner cin = new Scanner();
    readonly int[] dd = { 0, 1, 0, -1, 0 }; //→↓←↑
    readonly int mod = 1000000007;
    void chmax<T>(ref T a, T b) where T : IComparable<T> { a = a.CompareTo(b) < 0 ? b : a; }
    void chmin<T>(ref T a, T b) where T : IComparable<T> { a = a.CompareTo(b) < 0 ? a : b; }

    void solve()
    {
        int H = cin.nextint;
        int W = cin.nextint;
        var P = new string[H];
        for (int i = 0; i < H; i++)
        {
            P[i] = ReadLine();
        }
        double ans = double.MaxValue;



        int sy = -1, sx = -1;
        for (int r = 0; r < W; r++)
        {
            sx++;
            double cnt = 0;
            for (int i = 0; i < H; i++)
            {
                for (int j = 0; j < W; j++)
                {
                    if (P[i][j] == '1')
                    {
                        cnt += Sqrt(Pow(sy - i, 2) + Pow(sx - j, 2));
                    }
                }
            }
            chmin(ref ans, cnt);
        }
        sy = H; sx = -1;
        for (int r = 0; r < W; r++)
        {
            sx++;
            double cnt = 0;
            for (int i = 0; i < H; i++)
            {
                for (int j = 0; j < W; j++)
                {
                    if (P[i][j] == '1')
                    {
                        cnt += Sqrt(Pow(sy - i, 2) + Pow(sx - j, 2));
                    }
                }
            }
            chmin(ref ans, cnt);
        }

        sy = -1; sx = -1;
        for (int r = 0; r < H; r++)
        {
            sy++;
            double cnt = 0;
            for (int i = 0; i < H; i++)
            {
                for (int j = 0; j < W; j++)
                {
                    if (P[i][j] == '1')
                    {
                        cnt += Sqrt(Pow(sy - i, 2) + Pow(sx - j, 2));
                    }
                }
            }
            chmin(ref ans, cnt);
        }


        sy = -1; sx = W;
        for (int r = 0; r < H; r++)
        {
            sy++;
            double cnt = 0;
            for (int i = 0; i < H; i++)
            {
                for (int j = 0; j < W; j++)
                {
                    if (P[i][j] == '1')
                    {
                        cnt += Sqrt(Pow(sy - i, 2) + Pow(sx - j, 2));
                    }
                }
            }
            chmin(ref ans, cnt);
        }

        WriteLine(ans.ToString("F7"));
    }

}

class Scanner
{
    string[] s; int i;
    char[] cs = new char[] { ' ' };
    public Scanner() { s = new string[0]; i = 0; }
    public string[] scan { get { return ReadLine().Split(); } }
    public int[] scanint { get { return Array.ConvertAll(scan, int.Parse); } }
    public long[] scanlong { get { return Array.ConvertAll(scan, long.Parse); } }
    public double[] scandouble { get { return Array.ConvertAll(scan, double.Parse); } }
    public string next
    {
        get
        {
            if (i < s.Length) return s[i++];
            string st = ReadLine();
            while (st == "") st = ReadLine();
            s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
            i = 0;
            return next;
        }
    }
    public int nextint { get { return int.Parse(next); } }
    public long nextlong { get { return long.Parse(next); } }
    public double nextdouble { get { return double.Parse(next); } }
}