#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for(ll i = 0, i##_len = (n); i < i##_len; i++)
#define reps(i, s, n) for(ll i = (s), i##_len = (n); i < i##_len; i++)
#define rrep(i, n) for(ll i = (n) - 1; i >= 0; i--)
#define rreps(i, e, n) for(ll i = (n) - 1; i >= (e); i--)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((ll)(x).size())
#define len(x) ((ll)(x).length())

ll h, w;
vector<string> p;

double f(ll x, ll y) {
    double ans = 0;
    rep(i, h) {
        rep(j, w) {
            if (p[i][j] != '1') continue;
            ll dx = x - j;
            ll dy = y - i;
            ans += sqrt(dx * dx + dy * dy);
        }
    }
    return ans;
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    // ifstream in("input.txt");
    // cin.rdbuf(in.rdbuf());
    cin >> h >> w;
    p.resize(h);
    rep(i, h) cin >> p[i];
    double ans = 1e10;
    rep(i, w) {
        ans = min(ans, f(i, -1));
        ans = min(ans, f(i, h));
    }
    rep(i, h) {
        ans = min(ans, f(-1, i));
        ans = min(ans, f(w, i));
    }
    printf("%.10f\n", ans);
    return 0;
}