#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <array>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
#include <iterator>
using namespace std;

double solve(const vector<vector<bool> >& v, int py, int px)
{
    int h = v.size();
    int w = v[0].size();

    double ans = 0.0;
    for(int y=0; y<h; ++y){
        for(int x=0; x<w; ++x){
            if(v[y][x]){
                double dist = sqrt(pow(py - y, 2.0) + pow(px - x, 2.0));
                ans += dist;
            }
        }
    }
    return ans;
}

int main()
{
    int h, w;
    cin >> h >> w;
    vector<vector<bool> > v(h, vector<bool>(w));
    for(int y=0; y<h; ++y){
        for(int x=0; x<w; ++x){
            char c;
            cin >> c;
            v[y][x] = (c == '1');
        }
    }

    double ans = DBL_MAX;
    for(int y=0; y<h; ++y){
        ans = min(ans, solve(v, y, -1));
        ans = min(ans, solve(v, y, w));
    }
    for(int x=0; x<w; ++x){
        ans = min(ans, solve(v, -1, x));
        ans = min(ans, solve(v, h, x));
    }
    printf("%.10f\n", ans);

    return 0;
}