// https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
macro_rules! input {
    ($($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)*}
    };
}

macro_rules! read_value {
    ($next:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    };
    ($next:expr, $t:ty) => ($next().parse::<$t>().expect("Parse error"));
}

fn main() {
    input! {
        n: usize, m: usize,
        a: [usize; m],
    }
    let mut tbl = vec![false; n + 1];
    for a in a {
        tbl[a] = true;
    }
    let mut div = vec![vec![]; n + 1];
    for i in 1..n + 1 {
        for j in 1..n / i + 1 {
            div[i * j].push(i);
        }
    }
    let mut ans = 0;
    for i in (1..n + 1).rev() {
        if !tbl[i] {
            ans += 1;
            continue;
        }
        for &d in &div[i] {
            tbl[d] ^= true;
        }
    }
    println!("{}", ans);
}