fn main() {
    let length = std::env::args()
        .skip(1)
        .next()
        .unwrap()
        .parse::<u8>()
        .expect("");

    let mut list: Vec<String> = Vec::new();

    fill_list("".to_string(), length / 2, length, &mut list);

    for s in list {
        if check(s.clone()) {
            println!("{}", s);
        }
    }
}

fn fill_list(prefix: String, n_openings: u8, length: u8, v: &mut Vec<String>) {
    let openings = "({[";
    let closings = ")}]";
    let all = "(){}[]";

    if length == 0 {
        v.push(prefix.clone());
        return;
    }

    if prefix.is_empty() {
        for c in openings.chars() {
            let mut q = prefix.clone();

            q.push(c);

            fill_list(q, n_openings - 1, length - 1, v);
        }
    } else if length == 1 {
        for c in closings.chars() {
            let mut q = prefix.clone();

            q.push(c);

            fill_list(q, n_openings, length - 1, v);
        }
    } else if n_openings == 0 {
        for c in closings.chars() {
            let mut q = prefix.clone();

            q.push(c);

            fill_list(q, n_openings, length - 1, v);
        }
    } else {
        for c in all.chars() {
            let mut q = prefix.clone();

            q.push(c);

            match c {
                '(' => fill_list(q, n_openings - 1, length - 1, v),
                '{' => fill_list(q, n_openings - 1, length - 1, v),
                '[' => fill_list(q, n_openings - 1, length - 1, v),
                _ => fill_list(q, n_openings, length - 1, v),
            }
        }
    }
}

fn check(s: String) -> bool {
    let mut stack = Vec::new();

    for bracket in s.chars() {
        match bracket {
            '{' => stack.push(bracket),
            '[' => stack.push(bracket),
            '(' => stack.push(bracket),
            '}' => {
                if stack.last() == Some(&'{') {
                    stack.pop();
                } else {
                    stack.push(bracket);
                }
            }
            ']' => {
                if stack.last() == Some(&'[') {
                    stack.pop();
                } else {
                    stack.push(bracket);
                }
            }
            ')' => {
                if stack.last() == Some(&'(') {
                    stack.pop();
                } else {
                    stack.push(bracket);
                }
            }
            _ => unreachable!(),
        }
    }

    return stack.is_empty();
}