macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        let mut next = || { iter.next().unwrap() };
        input_inner!{next, $($r)*}
    };
    ($($r:tt)*) => {
        let stdin = std::io::stdin();
        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
        let mut next = move || -> String {
            bytes
                .by_ref()
                .map(|r| r.unwrap() as char)
                .skip_while(|c| c.is_whitespace())
                .take_while(|c| !c.is_whitespace())
                .collect()
        };
        input_inner!{next, $($r)*}
    };
}

macro_rules! input_inner {
    ($next:expr) => {};
    ($next:expr, ) => {};

    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };

    ($next:expr, mut $var:ident : $t:tt $($r:tt)*) => {
        let mut $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };
}

macro_rules! read_value {
    ($next:expr, ( $($t:tt),* )) => {
        ( $(read_value!($next, $t)),* )
    };

    ($next:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    };

    ($next:expr, [ $t:tt ]) => {
        {
            let len = read_value!($next, usize);
            (0..len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
        }
    };

    ($next:expr, chars) => {
        read_value!($next, String).chars().collect::<Vec<char>>()
    };

    ($next:expr, usize1) => {
        read_value!($next, usize) - 1
    };

    ($next:expr, $t:ty) => {
        $next().parse::<$t>().expect("Parse error")
    };
}

#[allow(unused_imports)]
use std::cmp::{min, max};

fn main() {
    input!{
        n: usize,
        m: usize,
        mut v: [usize; m]
    }
    if m == 1 {
        println!("{}", n);
        if n == 1 {
            println!("1");
            println!("1");
        } else {
            println!("{}", 2);
            println!("1 {}", n - 1);
        }
    } else if m == 2 {
        println!("{} {}", v[0], v[1]);
        if v[0] == 1 {
            println!("{}", 1);
            println!("{}", n);
        } else {
            println!("{}", 2);
            println!("{} {}", v[0] - 1, v[1] + 1);
        }
    } else {
        let odds = v.iter().filter(|&x| x % 2 == 1).count();
        if odds > 2 {
            println!("Impossible");
        } else {
            if odds > 0 && v[0] % 2 == 0 {
                for i in 1..m {
                    if v[i] % 2 == 1 {
                        let t = v[i];
                        v[i] = v[0];
                        v[0] = t;
                        break;
                    }
                }
            }
            if odds == 2 && v[m - 1] % 2 == 0 {
                for i in 1..m - 1 {
                    if v[i] % 2 == 1 {
                        let t = v[i];
                        v[i] = v[m - 1];
                        v[m - 1] = t;
                        break;
                    }
                }
            }
            for i in 0..m - 1 {
                print!("{} ", v[i]);
            }
            println!("{}", v[m - 1]);
            if v[0] == 1 {
                println!("{}", m - 1);
            } else {
                println!("{}", m);
                print!("{} ", v[0] - 1);
            }
            for i in 1..m - 1 {
                print!("{} ", v[i]);
            }
            println!("{}", v[m - 1] + 1);
        }
    }
}


Measured memory_bytes: 4352