#define _USE_MATH_DEFINES
#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define MT make_tuple
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
#define RT return
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
using vll = vector<ll>;

int H, W;
char P[55][55];

void solve() {
    cin >> H >> W;
    double ans = numeric_limits<double>::max();
    rep(y, H)cin >> (P[y + 1] + 1);
    rep(sy, H + 2)rep(sx, W + 2) {
        int z = (sy == 0) + (sy == H + 1) + (sx == 0) + (sx == W + 1);
        if (z != 1)continue;
        double sm = 0;
        FOR(y, 1, H + 1)FOR(x, 1, W + 1)if (P[y][x] == '1') {
            sm += hypot(sy - y, sx - x);
        }
        smin(ans, sm);
    }
    cout << ans << endl;
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout << fixed << setprecision(15);
	solve();
	return 0;
}