use std::collections::HashMap;
use std::io::Write;
/* ----------------------------------------------- */
fn run<W: Write>(sc: &mut scanner::Scanner, out: &mut std::io::BufWriter<W>) {
    let n: usize = sc.next();
    let m: usize = sc.next();
    let v: Vec<usize> = sc.next_vec(n);

    let mut map = HashMap::new();
    for x in v {
        let p = map.entry(x % m).or_insert(0);
        *p += 1
    }
    let mut ans = 0;
    for x in 1..(m + 1) >> 1 {
        ans += std::cmp::max(map.get(&x).unwrap_or(&0), map.get(&(m - x)).unwrap_or(&0));
    }
    ans += std::cmp::min(1, *map.get(&0).unwrap_or(&0));
    if m & 1 == 0 {
        ans += std::cmp::min(1, *map.get(&(m >> 1)).unwrap_or(&0));
    }
    writeln!(out, "{:?}", ans).ok();
}

/* ----------------------------------------------- */
#[allow(dead_code)]
mod scanner {
    use std::str::FromStr;
    pub struct Scanner<'a> {
        it: std::str::SplitWhitespace<'a>,
    }
    impl<'a> Scanner<'a> {
        pub fn new(s: &'a String) -> Scanner<'a> {
            Scanner {
                it: s.split_whitespace(),
            }
        }
        pub fn next<T: FromStr>(&mut self) -> T {
            self.it.next().unwrap().parse::<T>().ok().unwrap()
        }
        pub fn next_bytes(&mut self) -> Vec<u8> {
            self.it.next().unwrap().bytes().collect()
        }
        pub fn next_chars(&mut self) -> Vec<char> {
            self.it.next().unwrap().chars().collect()
        }
        pub fn next_vec<T: FromStr>(&mut self, len: usize) -> Vec<T> {
            (0..len).map(|_| self.next()).collect()
        }
    }
}
/* ----------------------------------------------- */
fn main() {
    use std::io::Read;
    let mut s = String::new();
    std::io::stdin().read_to_string(&mut s).unwrap();
    let mut sc = scanner::Scanner::new(&s);
    let out = std::io::stdout();
    let mut out = std::io::BufWriter::new(out.lock());
    run(&mut sc, &mut out);
}
/* ----------------------------------------------- */