#include <bits/stdc++.h>


using namespace std;
typedef long long ll;
#define REP(i,n) for(int i=0; i<int(n); i++)
#define FOR(i,m,n) for(int i=int(m); i<int(n); i++)
#define ALL(obj) (obj).begin(),(obj).end()
#define VI vector<int>
#define VLL vector<long long>
#define VVI vector<vector<int>>
#define VVLL vector<vector<long long>>
#define VC vector<char>
#define VS vector<string>
#define VVC vector<vector<char>>
#define VB vector<bool>
#define VVB vector<vector<bool>>
#define fore(i,a) for(auto &i:a)

typedef pair <int, int> P;
template<class T> bool chmax(T &a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> bool chmin(T &a, T b) { if (a > b) { a = b; return true; } return false; }
const int  INF = 1 << 29;
const ll INFL = 1LL << 60;
const ll mod = 1000000007;

char a[55][55];
int h, w;
double ans = 10000000000.0;


void f(int aa, int b) {
	double c = 0;
	FOR(i, 0, h + 2)FOR(j, 0, w + 2) {
		if (a[i][j] == '1') {
			c += sqrt((i - aa)*(i - aa) + ((j - b)*(j - b)));

		}
	}
	ans = min(ans, c);
}

int main() {

	cin >> h >> w;
	REP(i, h)REP(j, w)cin >> a[i + 1][j + 1];

	REP(i, 52)REP(j, 52) {
		int cnt = 0;
		if (i == 0)cnt++;
		if (i == h + 1)cnt++;
		if (j == 0)cnt++;
		if (j == w + 1)cnt++;
		if (cnt != 1)continue;
		f(i, j);
	}

	cout << fixed << setprecision(15) << ans << endl;


}