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