use std::io::{stdin, Read, StdinLock};
use std::str::FromStr;
use std::iter::FromIterator;

fn main() {
    let cin = stdin();
    let mut scan = Scanner::new(cin.lock());
    let n = scan.read::<usize>();
    let k = scan.read::<usize>();
    let q = n / (k * k);
    let rem = n % (k * k);
    let mut p = 0;
    {
        let mut i = 1;
        while p < rem {
            p += i * i;
            i += 1;
        }
    }
    let rest_sz = (p as f64).sqrt() as usize;
    let w = q * k + rest_sz;
    let mut ret = vec![vec!['.';w];w];
    for i in 0..q {
        set_sq(&mut ret, i * k, k, k * k);
    }
    set_sq(&mut ret, q * k, rest_sz, rem);
    println!("{}", w);
    for y in 0..w {
        println!("{}", ret[y].iter().cloned().collect::<String>());
    }
}

fn set_sq(ret: &mut Vec<Vec<char>>, prefix: usize, size: usize, mut cnt: usize) {
    for y in prefix..prefix + size {
        for x in prefix..prefix + size {
            if cnt == 0 {return;}
            ret[y][x] = '#';
            cnt -= 1;
        }
    }
}

// region template
#[allow(dead_code)]
fn iu(i: i64) -> usize { i as usize }

#[allow(dead_code)]
fn ui(i: usize) -> i64 { i as i64 }

#[allow(dead_code, deprecated)]
fn join<T: std::fmt::Display>(slice: &[T], sep: &str) -> String {
    let strings = slice.iter().map(|t| format!("{}", t)).collect::<Vec<_>>();
    strings.connect(sep)
}

#[allow(dead_code)]
fn arr<'a, S, T>(n: usize, mut f: S) -> Vec<T> where S: FnMut(usize) -> T + 'a {
    (0..n).map(|i| f(i)).collect::<Vec<T>>()
}

#[allow(dead_code)]
fn alt<S, T>(v: Vec<S>) -> T where T: FromIterator<S> {
    v.into_iter().collect::<T>()
}

#[allow(dead_code)]
fn dup<S, T>(v: &[S]) -> T where T: FromIterator<S>, S: Clone {
    v.iter().cloned().collect::<T>()
}

struct Scanner<'a> {
    cin: StdinLock<'a>,
}

#[allow(dead_code)]
impl<'a> Scanner<'a> {
    fn new(cin: StdinLock<'a>) -> Scanner<'a> {
        Scanner { cin: cin }
    }

    fn read1<T: FromStr>(&mut self) -> Option<T> {
        let token = self.cin.by_ref().bytes().map(|c| c.unwrap() as char)
            .skip_while(|c| c.is_whitespace())
            .take_while(|c| !c.is_whitespace())
            .collect::<String>();
        token.parse::<T>().ok()
    }

    fn read<T: FromStr>(&mut self) -> T {
        self.read1().unwrap()
    }

    fn readn<T: FromStr>(&mut self, n: usize) -> Vec<T> {
        (0..n).map(|_| self.read::<T>()).collect()
    }

    fn chars(&mut self) -> Vec<char> {
        self.read::<String>().chars().collect()
    }
}
// endregion