#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <string>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <stdio.h>
using namespace std;
#define int long long
int MOD = 1000000007;
double solve(vector<pair<int, int> > &vp, int x, int y) {
	double res = 0;
	for (int i = 0; i < vp.size(); i++) {
		res += sqrt((vp[i].first - x)*(vp[i].first - x) + (vp[i].second - y)*(vp[i].second - y));
	}
	return res;
}
signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	int H, W;
	cin >> H >> W;
	vector<string> S(H);
	double res = 1e18;
	vector<pair<int, int> > vp;
	for (int i = 0; i < H; i++) {
		cin >> S[i];
		for (int j = 0; j < W; j++) {
			if (S[i][j] == '1') {
				vp.emplace_back(i + 1, j + 1);
			}
		}
	}
	for (int i = 0; i < H; i++) {
		res = min(res, solve(vp, i, 0));
		res = min(res, solve(vp, i, W + 1));
	}
	for (int i = 0; i < W; i++) {
		res = min(res, solve(vp, H + 1, i));
		res = min(res, solve(vp, 0, i));
	}
	cout << fixed << setprecision(15) << res << endl;
}