using System;
using System.Collections.Generic;
using System.Linq;
using static System.Console;

class Program
{
    static void Main()
    {
        var HW = ReadLine().Split().Select(int.Parse).ToArray();
        var H = HW[0];
        var W = HW[1];
        var l = new List<int[]>();
        for (int i = 0; i < H; i++)
        {
            var line = ReadLine();
            for (int j = 0; j < W; j++)
            {
                if (line[j] == '1') l.Add(new[] { i + 1, j + 1 });
            }
        }
        var ans = (double)int.MaxValue;
        for (int i = 1; i <= H; i++)
        {
            ans = Math.Min(calc(l, i, 0), ans);
            ans = Math.Min(calc(l, i, W + 1), ans);
        }
        for (int i = 1; i <= W; i++)
        {
            ans = Math.Min(calc(l, 0, i), ans);
            ans = Math.Min(calc(l, H + 1, i), ans);
        }
        WriteLine(ans);
    }

    static double calc(List<int[]> l, int x, int y)
    {
        var r = 0.0;
        foreach (var i in l)
        {
            r += Math.Sqrt((i[0] - x) * (i[0] - x) + (i[1] - y) * (i[1] - y));
        }
        return r;
    }
}