#pragma region 宣言部分
#include <iostream>
#include <algorithm>
#include <bitset>
#include<cstdio>
#include <complex>
#include <deque>
#include <iterator>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <utility>
#include <vector>
typedef long long ll;
#define REP(i,n) for(int i = 0;i < (n);i++)
#define rep(i,m,n) for(int i = (m);i < (n);i++)
#define P pair<int,int>
#define pb push_back
#define mk make_pair
using namespace std;
#define Vec(a) vector <int> a
const int INF = 1 << 20;
const int MOD = 1e9+7;

#pragma endregion



int main(){
  int h,w;
  cin >> h >> w;
  double b[h+2][w+2];
  string s[h];
  REP(i,h){
      cin >> s[i];
  }
  REP(i,h+2){
      REP(j,w+2){
          b[i][j] = 100000;
      }
  }
  double sum = 100000.0;
  double res = 0.0;
  rep(i,1,w+1){
      res = 0.0;
      rep(j,1,h+1){
          rep(k,1,w+1){
              if(s[j-1][k-1] == '1'){
                  res += (double)sqrt((double)j*(double)j + (double)abs(i-k)*(double)abs(i-k));
                  //cout << res << endl;
                  //cout << j << k << endl;

              }
          }
      }
      //cout << res << endl;
      sum = min(sum,res);
  }
  rep(i,1,w+1){
      res = 0.0;
      rep(j,1,h+1){
          rep(k,1,w+1){
              //b[j][k] = min(b[j][k], sqrt((h+1 - j)*(h+1-j) + abs(k-i)* abs(k-i)));
              if(s[j-1][k-1] == '1'){
                  res += (double)sqrt((double)(h+1-j)*(double)(h+1-j) + (double)abs(i-k)*(double)abs(i-k));

              }
          }
      }
      sum = min(sum,res);
  }
  rep(i,1,h+1){
      res = 0.0;
      rep(j,1,h+1){
          rep(k,1,w+1){
              //b[j][k] = min(b[j][k], sqrt(abs(j-i)*abs(j-i) + k*k));
              if(s[j-1][k-1] == '1'){
                  res += (double)sqrt((double)abs(j-i)*(double)abs(j-i) + (double)k*(double)k);

              }
          }
      }
      sum = min(res,sum);
  }
  rep(i,1,h+1){
      res = 0.0;
      rep(j,1,h+1){
          rep(k,1,w+1){
              //b[j][k] = min(b[j][k], sqrt(abs(j-i)*abs(j-i) + (w+1-k)*(w+1-k)));
              if(s[j-1][k-1] == '1'){
                  res += (double)sqrt((double)abs(j-i)*(double)abs(j-i) + (double)(w+1-k)*(double)(w+1-k));

              }
          }
      }
      sum = min(res,sum);
  }
  printf("%.8lf\n",sum);
  //cout << sum << endl;
  return 0;
}