#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
#define rep(i,l,r) for(int i=(l);i<(r);i++)
#define fcout cout << fixed << setprecision(10)
int h,w;
double paint(int a,int b,array<array<bool,51>,51> p){
    double ans=0;
    rep(i,1,h+1)rep(j,1,w+1)if(p[i][j])ans+=sqrt((a-i)*(a-i)+(b-j)*(b-j));
    return ans;
}
int main(){
    cin>>h>>w;
    array<array<bool,51>,51> p;
    string s;
    rep(i,1,h+1){
        cin>>s;
        rep(j,1,w+1)p[i][j]=s[j-1]-'0';
    }
    double mn=1e20,sum;
    rep(i,1,h+1){
        sum=paint(i,0,p);
        if(sum<mn)mn=sum;
    }
    rep(i,1,h+1){
        sum=paint(i,w+1,p);
        if(sum<mn)mn=sum;
    }
    rep(i,1,w+1){
        sum=paint(0,i,p);
        if(sum<mn)mn=sum;
    }
    rep(i,1,w+1){
        sum=paint(h+1,i,p);
        if(sum<mn)mn=sum;
    }
    fcout<<mn;
}