// -*- coding:utf-8-unix -*-
// #![feature(map_first_last)]
#![allow(dead_code)]
#![allow(unused_imports)]
#![allow(unused_macros)]
use std::arch::x86_64::_XCR_XFEATURE_ENABLED_MASK;
use std::cmp::Ordering::*;
use std::collections::*;
use std::convert::*;
use std::convert::{From, Into};
use std::f64::consts::PI;
use std::fmt::Debug;
use std::fmt::Display;
use std::fs::File;
use std::hash::Hash;
use std::io::prelude::*;
use std::io::*;
use std::marker::Copy;
use std::mem::*;
use std::ops::Bound::*;
use std::ops::{Add, Mul, Neg, Sub};
use std::str;
use std::vec;
use std::{cmp, process::Output};
use std::{cmp::Ordering, env::consts::DLL_PREFIX};
const INF: i64 = 1223372036854775807;
const UINF: usize = INF as usize;
// const FINF: f64 = 122337203685.0;
const LINF: i64 = 2147483647;
const FINF: f64 = LINF as f64;
const INF128: i128 = 1223372036854775807000000000000;
const MOD: i64 = 1000000007;
// const MOD: i64 = 998244353;

const MPI: f64 = 3.14159265358979323846264338327950288f64;
// const MOD: i64 = INF;

const UMOD: usize = MOD as usize;
use std::cmp::*;
use std::collections::*;
use std::io::stdin;
use std::io::stdout;
use std::io::Write;

macro_rules! p {
    ($x:expr) => {
        println!("{}", $x);
    };
}
macro_rules! d {
    ($x:expr) => {
        println!("{:?}", $x);
    };
}

macro_rules! chmin {
    ($base:expr, $($cmps:expr),+ $(,)*) => {{
        let cmp_min = min!($($cmps),+);
        if $base > cmp_min {
            $base = cmp_min;
            true
        } else {
            false
        }
    }};
}

macro_rules! chmax {
    ($base:expr, $($cmps:expr),+ $(,)*) => {{
        let cmp_max = max!($($cmps),+);
        if $base < cmp_max {
            $base = cmp_max;
            true
        } else {
            false
        }
    }};
}

macro_rules! min {
    ($a:expr $(,)*) => {{
        $a
    }};
    ($a:expr, $b:expr $(,)*) => {{
        std::cmp::min($a, $b)
    }};
    ($a:expr, $($rest:expr),+ $(,)*) => {{
        std::cmp::min($a, min!($($rest),+))
    }};
}

macro_rules! max {
    ($a:expr $(,)*) => {{
        $a
    }};
    ($a:expr, $b:expr $(,)*) => {{
        std::cmp::max($a, $b)
    }};
    ($a:expr, $($rest:expr),+ $(,)*) => {{
        std::cmp::max($a, max!($($rest),+))
    }};
}

// use str::Chars;

// use str::Chars;
#[allow(dead_code)]
fn read<T: std::str::FromStr>() -> T {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    s.trim().parse().ok().unwrap()
}

#[allow(dead_code)]
fn readi() -> (i64) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    iter.next().unwrap().parse::<i64>().unwrap()
}

#[allow(dead_code)]
fn read_vec<T: std::str::FromStr>() -> Vec<T> {
    read::<String>()
        .split_whitespace()
        .map(|e| e.parse().ok().unwrap())
        .collect()
}
#[allow(dead_code)]
fn read_mat<T: std::str::FromStr>(n: u32) -> Vec<Vec<T>> {
    (0..n).map(|_| read_vec()).collect()
}

#[allow(dead_code)]
fn readii() -> (i64, i64) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<i64>().unwrap(),
        iter.next().unwrap().parse::<i64>().unwrap(),
    )
}

fn readff() -> (f64, f64) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<f64>().unwrap(),
        iter.next().unwrap().parse::<f64>().unwrap(),
    )
}

#[allow(dead_code)]
fn readiii() -> (i64, i64, i64) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<i64>().unwrap(),
        iter.next().unwrap().parse::<i64>().unwrap(),
        iter.next().unwrap().parse::<i64>().unwrap(),
    )
}
#[allow(dead_code)]
fn readuu() -> (usize, usize) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<usize>().unwrap(),
        iter.next().unwrap().parse::<usize>().unwrap(),
    )
}

fn readcc() -> (char, char) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<char>().unwrap(),
        iter.next().unwrap().parse::<char>().unwrap(),
    )
}

#[allow(dead_code)]
fn readuuu() -> (usize, usize, usize) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<usize>().unwrap(),
        iter.next().unwrap().parse::<usize>().unwrap(),
        iter.next().unwrap().parse::<usize>().unwrap(),
    )
}

#[allow(dead_code)]
fn readuuuu() -> (usize, usize, usize, usize) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<usize>().unwrap(),
        iter.next().unwrap().parse::<usize>().unwrap(),
        iter.next().unwrap().parse::<usize>().unwrap(),
        iter.next().unwrap().parse::<usize>().unwrap(),
    )
}

fn readiiii() -> (i64, i64, i64, i64) {
    let mut str = String::new();
    let _ = stdin().read_line(&mut str).unwrap();
    let mut iter = str.split_whitespace();
    (
        iter.next().unwrap().parse::<i64>().unwrap(),
        iter.next().unwrap().parse::<i64>().unwrap(),
        iter.next().unwrap().parse::<i64>().unwrap(),
        iter.next().unwrap().parse::<i64>().unwrap(),
    )
}

pub mod dinic {
    #[derive(Clone, Copy, Debug)]
    struct Edge {
        to: usize,
        cap: i64,
        rev: usize,
    }
    pub struct Network {
        g: Vec<Vec<Edge>>,
        level: Vec<Option<usize>>,
        iter: Vec<usize>,
    }
    #[doc = "direct flow graph. O(EV^2)"]
    impl Network {
        pub fn new(n: usize) -> Network {
            Network {
                g: vec![vec![]; n],
                level: vec![None; n],
                iter: vec![0; n],
            }
        }
        pub fn add_edge(&mut self, from: usize, to: usize, cap: i64) {
            assert!(cap >= 0);

            let from_rev = self.g[to].len();
            let to_rev = self.g[from].len();
            self.g[from].push(Edge {
                to: to,
                cap: cap,
                rev: from_rev,
            });
            self.g[to].push(Edge {
                to: from,
                cap: 0,
                rev: to_rev,
            });
        }
        fn n(&self) -> usize {
            self.g.len()
        }
        fn bfs(&mut self, s: usize) {
            self.level = vec![None; self.n()];
            let mut q = std::collections::VecDeque::new();
            q.push_back(s);
            self.level[s] = Some(0);
            while let Some(v) = q.pop_front() {
                for e in &self.g[v] {
                    if e.cap > 0 && self.level[e.to].is_none() {
                        self.level[e.to] = self.level[v].map(|x| x + 1);
                        q.push_back(e.to);
                    }
                }
            }
        }
        fn dfs(&mut self, v: usize, t: usize, f: i64) -> i64 {
            if v == t {
                return f;
            }
            let iter_v_cur = self.iter[v];
            for i in iter_v_cur..self.g[v].len() {
                let e = self.g[v][i].clone();
                if e.cap > 0 && self.level[v] < self.level[e.to] {
                    let d = self.dfs(e.to, t, std::cmp::min(f, e.cap));
                    if d > 0 {
                        self.g[v][i].cap -= d;
                        self.g[e.to][e.rev].cap += d;
                        return d;
                    }
                }
                self.iter[v] += 1;
            }
            return 0;
        }
        pub fn max_flow(&mut self, s: usize, t: usize) -> i64 {
            let mut flow = 0;
            loop {
                self.bfs(s);
                // finally if we could not find any path to t then return flow
                if self.level[t].is_none() {
                    return flow;
                }

                let INF = 2_000_000_001;
                self.iter = vec![0; self.n()];
                let mut f = self.dfs(s, t, INF);
                while f > 0 {
                    flow += f;
                    f = self.dfs(s, t, INF);
                }
            }
        }
    }
}
// #[test]
// fn test_dinic() {
//     use dinic::*;
//     let mut nw = Network::new(5);

//     let conns = [
//         (0, 1, 10),
//         (0, 2, 2),
//         (1, 2, 6),
//         (1, 3, 6),
//         (3, 2, 3),
//         (2, 4, 5),
//         (3, 4, 8),
//     ];

//     for conn in &conns {
//         nw.add_edge(conn.0, conn.1, conn.2);
//     }

//     assert_eq!(nw.max_flow(0, 4), 11);
// }
/// Equivalent to std::lowerbound and std::upperbound in c++
pub trait BinarySearch<T> {
    fn lower_bound(&self, x: &T) -> usize;
    fn upper_bound(&self, x: &T) -> usize;
}
impl<T: Ord> BinarySearch<T> for [T] {
    fn lower_bound(&self, x: &T) -> usize {
        let mut low = 0;
        let mut high = self.len();
        while low != high {
            let mid = (low + high) / 2;
            match self[mid].cmp(x) {
                Ordering::Less => {
                    low = mid + 1;
                }
                Ordering::Equal | Ordering::Greater => {
                    high = mid;
                }
            }
        }
        low
    }
    fn upper_bound(&self, x: &T) -> usize {
        let mut low = 0;
        let mut high = self.len();
        while low != high {
            let mid = (low + high) / 2;
            match self[mid].cmp(x) {
                Ordering::Less | Ordering::Equal => {
                    low = mid + 1;
                }
                Ordering::Greater => {
                    high = mid;
                }
            }
        }
        low
    }
}
#[derive(PartialEq, Eq, Clone, Debug)]
enum Inf<T> {
    Val(T),
    Inf,
}
impl<T: Ord> Inf<T> {
    #[allow(dead_code)]
    fn val(self) -> Option<T> {
        match self {
            Inf::Val(v) => Some(v),
            _ => None,
        }
    }
}
impl<T: PartialOrd> PartialOrd for Inf<T> {
    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
        match (self, other) {
            (&Inf::Inf, &Inf::Inf) => Some(Ordering::Equal),
            (&Inf::Inf, &Inf::Val(_)) => Some(Ordering::Greater),
            (&Inf::Val(_), &Inf::Inf) => Some(Ordering::Less),
            (&Inf::Val(ref a), &Inf::Val(ref b)) => a.partial_cmp(b),
        }
    }
}
impl<T: Ord> Ord for Inf<T> {
    fn cmp(&self, other: &Self) -> Ordering {
        match (self, other) {
            (&Inf::Inf, &Inf::Inf) => Ordering::Equal,
            (&Inf::Inf, &Inf::Val(_)) => Ordering::Greater,
            (&Inf::Val(_), &Inf::Inf) => Ordering::Less,
            (&Inf::Val(ref a), &Inf::Val(ref b)) => a.cmp(b),
        }
    }
}
#[allow(dead_code)]
/// Calculate length of Longest Increasing Subsequence. O(N log N)
pub fn lis<T: Ord>(seq: &[T]) -> Vec<Option<&T>> {
    let mut dp: Vec<Inf<&T>> = vec![Inf::Inf; seq.len() + 1];
    for x in seq.iter() {
        let i = dp.lower_bound(&Inf::Val(x));
        dp[i] = Inf::Val(x);
    }
    let mut res = vec![];
    for i in dp {
        if i != Inf::Inf {
            res.push(i.val());
        }
    }
    return res;
}
fn solve() {
    use dinic::*;
    let (n, m, q) = readuuu();
    let mut data = vec![];
    for i in 0..q {
        let (a, b) = readuu();
        data.push((b, a));
    }
    // data.sort();
    for i in 0..data.len() {
        data[i] = (data[i].1, data[i].0);
    }
    let li = lis(&data);
    // d!(li);
    // println!("{:?}", li);
    let mut st = BTreeSet::new();
    for i in li {
        st.insert(i.unwrap().1);
    }
    println!("{:?}", st.len());
    // let mut nw = Network::new(n + m + 2);

    // // let conns = [
    // //     (0, 1, 10),
    // //     (0, 2, 2),
    // //     (1, 2, 6),
    // //     (1, 3, 6),
    // //     (3, 2, 3),
    // //     (2, 4, 5),
    // //     (3, 4, 8),
    // // ];
    // let mut conns = vec![(0, 0, 0); 0];
    // let mut src = 0;
    // let mut dst = n + m + 1;
    // for i in 0..n {
    //     conns.push((src, i + 1, 1));
    // }
    // for i in 0..m {
    //     conns.push((i + 1 + n, dst, 1));
    // }
    // for i in 0..q {
    //     let (a, b) = readuu();
    //     if a >= b {
    //         continue;
    //     }
    //     conns.push((a, n + b, 1));
    // }

    // for conn in &conns {
    //     nw.add_edge(conn.0, conn.1, conn.2);
    // }
    // let mut res = nw.max_flow(src, dst);
    // println!("{:?}", res);

    return;
}
fn main() {
    solve();
    return;
}