use std::io::{Read, stdin};

fn main() {
    let mut buf = String::new();
    stdin().read_to_string(&mut buf).unwrap();
    let mut tok = buf.split_whitespace();
    let mut get = || tok.next().unwrap();
    macro_rules! get {
        ($t:ty) => (get().parse::<$t>().unwrap());
        () => (get!(i64));
    }
    
    let h = get!();
    let w = get!();
    
    let mut paper = vec![];
    
    for _ in 0..h {
        paper.push(get().as_bytes());
    }
    
    let mut ans = std::f64::MAX;
    
    for y0 in 0..h {
        let tmp = calc(h, w, 0, y0+1, &paper);
        if tmp < ans {
            ans = tmp;
        }
        let tmp = calc(h, w, w+1, y0+1, &paper);
        if tmp < ans {
            ans = tmp;
        }
    }
    for x0 in 0..w {
        let tmp = calc(h, w, x0+1, 0, &paper);
        if tmp < ans {
            ans = tmp;
        }
        let tmp = calc(h, w, x0+1, h+1, &paper);
        if tmp < ans {
            ans = tmp;
        }
    }
    
    println!("{}", ans);
}

fn calc(h: i64, w: i64, x0: i64, y0: i64, paper: &Vec<&[u8]>) -> f64 {
    let mut ret = 0.0;
    for y1 in 0..h {
        for x1 in 0..w {
            if paper[y1 as usize][x1 as usize] == b'1' {
                ret += dist(x0, y0, x1+1, y1+1);
            }
        }
    }
    ret
}

fn dist(x0: i64, y0: i64, x1: i64, y1: i64) -> f64 {
    let dx = (x1 - x0) as f64;
    let dy = (y1 - y0) as f64;
    (dx * dx + dy * dy).sqrt()
}