#![allow(unused_imports, unused_macros, dead_code)]

macro_rules! min {
    (.. $x:expr) => {{
        let mut it = $x.iter();
        it.next().map(|z| it.fold(z, |x, y| min!(x, y)))
    }};
    ($x:expr) => ($x);
    ($x:expr, $($ys:expr),*) => {{
        let t = min!($($ys),*);
        if $x < t { $x } else { t }
    }}
}
macro_rules! max {
    (.. $x:expr) => {{
        let mut it = $x.iter();
        it.next().map(|z| it.fold(z, |x, y| max!(x, y)))
    }};
    ($x:expr) => ($x);
    ($x:expr, $($ys:expr),*) => {{
        let t = max!($($ys),*);
        if $x > t { $x } else { t }
    }}
}
macro_rules! ewriteln {
    ($($args:expr),*) => { let _ = writeln!(&mut std::io::stderr(), $($args),*); };
}
macro_rules! trace {
    ($x:expr) => { ewriteln!(">>> {} = {:?}", stringify!($x), $x) };
    ($($xs:expr),*) => { trace!(($($xs),*)) }
}
macro_rules! put {
    (.. $x:expr) => {{
        let mut it = $x.iter();
        if let Some(x) = it.next() { print!("{}", x); }
        for x in it { print!(" {}", x); }
        println!("");
    }};
    ($x:expr) => { println!("{}", $x) };
    ($x:expr, $($xs:expr),*) => { print!("{} ", $x); put!($($xs),*) }
}

const M: i64 = 1_000_000_007;

fn bomb_filter(xs: &Vec<(usize, usize)>) -> (usize, Vec<(usize, usize)>) {
    let mut freq = vec![0; 300002];
    for &(x, _) in xs.iter() {
        freq[x] += 1;
    }
    let mut hist: Vec<_> = (0..300002).map(|i| (i, freq[i])).collect();
    hist.sort_by_key(|&item| item.1);
    hist.reverse();
    let (xdel, f) = hist[0];
    let filtered = xs.iter().filter(|&(x, _)| *x != xdel).cloned().collect();
    (f, filtered)
}

fn transpose(xs: &Vec<(usize, usize)>) -> Vec<(usize, usize)> {
    xs.iter().map(|&(x, y)| (y, x)).collect()
}

fn main() {
    let mut sc = Scanner::new();
    let _h: usize = sc.cin();
    let _w: usize = sc.cin();
    let n: usize = sc.cin();

    let b: Vec<_> = (0..n)
        .map(|_| {
            let x: usize = sc.cin();
            let y: usize = sc.cin();
            (x, y)
        })
        .collect();

    let mut ans = 0;
    {
        let (f, c) = bomb_filter(&b);
        let (g, _) = bomb_filter(&transpose(&c));
        ans = max!(ans, f + g);
    }
    {
        let (f, c) = bomb_filter(&transpose(&b));
        let (g, _) = bomb_filter(&transpose(&c));
        ans = max!(ans, f + g);
    }

    put!(ans);
}

use std::collections::VecDeque;
use std::io::{self, Write};
use std::str::FromStr;

struct Scanner {
    stdin: io::Stdin,
    buffer: VecDeque<String>,
}
impl Scanner {
    fn new() -> Self {
        Scanner {
            stdin: io::stdin(),
            buffer: VecDeque::new(),
        }
    }
    fn cin<T: FromStr>(&mut self) -> T {
        while self.buffer.len() == 0 {
            let mut line = String::new();
            let _ = self.stdin.read_line(&mut line);
            for w in line.split_whitespace() {
                self.buffer.push_back(String::from(w));
            }
        }
        self.buffer.pop_front().unwrap().parse::<T>().ok().unwrap()
    }
    fn chars(&mut self) -> Vec<char> {
        self.cin::<String>().chars().collect()
    }
    fn vec<T: FromStr>(&mut self, n: usize) -> Vec<T> {
        (0..n).map(|_| self.cin()).collect()
    }
}


Measured memory_bytes: 33796