// 基本テンプレート
 
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <string>
#include <cstring>
#include <deque>
#include <list>
#include <queue>
#include <stack>
#include <vector>
#include <utility>
#include <algorithm>
#include <map>
#include <set>
#include <complex>
#include <cmath>
#include <limits>
#include <cfloat>
#include <climits>
#include <ctime>
#include <cassert>
#include <numeric>
#include <fstream>
#include <functional>
using namespace std;
 
#define rep(i,a,n) for(int (i)=(a); (i)<(n); (i)++)
#define repq(i,a,n) for(int (i)=(a); (i)<=(n); (i)++)
#define repr(i,a,n) for(int (i)=(a); (i)>=(n); (i)--)
#define debug(...) fprintf(stderr, __VA_ARGS__)
#define int long long int
 
template<typename T> void chmax(T &a, T b) {a = max(a, b);}
template<typename T> void chmin(T &a, T b) {a = min(a, b);}
template<typename T> void chadd(T &a, T b) {a = a + b;}
 
typedef pair<int, int> pii;
typedef long long ll;
 
int dx[] = {0, 0, 1, -1};
int dy[] = {1, -1, 0, 0};
const ll INF = 1001001001001001LL;
const ll MOD = 1000000007LL;

int H, W;
char board[60][60];

double solve(int lx, int rx, int ly, int ry) {
    double mi = 1e100;
    for(int x=lx; x<=rx; x++) {
        for(int y=ly; y<=ry; y++) {
            double sum = 0.0;
            for(int i=0; i<H; i++) {
                for(int j=0; j<W; j++) {
                    if(board[i][j] == '0') continue;
                    int Dx = x - i, Dy = y - j;
                    sum += sqrt((double)Dx * Dx + Dy * Dy);
                }
            }
            // printf("x = %lld, y = %lld, sum = %.12f\n", x, y, sum);
            chmin(mi, sum);
        }
    }
    return mi;
}

signed main() {
    cin >> H >> W;
    for(int i=0; i<H; i++) {
        for(int j=0; j<W; j++) {
            cin >> board[i][j];
        }
    }

    double ans = 1e100;
    chmin(ans, solve(0, H-1, -1, -1));
    chmin(ans, solve(0, H-1, W, W));
    chmin(ans, solve(-1, -1, 0, W-1));
    chmin(ans, solve(H, H, 0, W-1));
    cout << setprecision(12) << ans << endl;
    return 0;
}