#include <iostream>
#include <iomanip>
#include <cmath>
#include <vector>

using ldouble = long double;

void solve() {
    int h, w;
    std::cin >> h >> w;

    std::vector<std::pair<ldouble, ldouble>> ps;
    for (int x = 1; x <= h; ++x) {
        for (int y = 1; y <= w; ++y) {
            char c;
            std::cin >> c;
            if (c == '1') ps.emplace_back(x, y);
        }
    }

    ldouble ans = 1e20;
    for (int x = 0; x <= h + 1; ++x) {
        for (int y = 0; y <= w + 1; ++y) {
            int cond = 0;
            if (x == 0 || x == h + 1) ++cond;
            if (y == 0 || y == w + 1) ++cond;
            if (cond != 1) continue;

            ldouble sum = 0;
            for (auto& p : ps) {
                sum += std::hypot(x - p.first, y - p.second);
            }

            ans = std::min(ans, sum);
        }
    }

    std::cout << std::fixed << std::setprecision(10)
              << ans << std::endl;
}

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    solve();

    return 0;
}