fn main() {
    let mut nk = String::new();
    std::io::stdin().read_line(&mut nk).ok();
    let nk: Vec<usize> = nk.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let n = nk[0];
    let k = nk[1];

    let mut result = 1usize;
    let mut cnt = 1usize;
    while cnt < n {
        result += 1;
        let rest = cnt % (k*k);
        cnt -= rest;
        let temp = result % k;
        cnt += if temp == 0 { k * k } else { temp * temp };
    }
    println!("{}", result);
    let mut grid = vec![vec!["."; result]; result];
    let mut cnt = 0usize;
    for i in 0..result {
        let start = i/k*k;
        for j in 0..k {
            if cnt == n { break; }
            if start+j >= result { break; }
            grid[i][start+j] = "#";
            cnt += 1;
        }
        if cnt == n { break; }
    }
    for i in 0..result {
        println!("{}", grid[i].join(""));
    }
}