#line 2 "/Users/kaage/Desktop/ProgrammingWorkspace/library/other/template.hpp"
#define _CRT_SECURE_NO_WARNINGS
#pragma target("avx2")
#pragma optimize("O3")
#pragma optimize("unroll-loops")
#include <algorithm>
#include <bitset>
#include <cassert>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <ctime>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <memory>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <string.h>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
#define rep(i,n) for(int i=0;i<(n);i++)
#define REP(i,n) for(int i=1;i<=(n);i++)
#define all(V) V.begin(),V.end()
typedef unsigned int uint;
typedef long long lint;
typedef unsigned long long ulint;
typedef std::pair<int, int> P;
typedef std::pair<lint, lint> LP;
constexpr int INF = INT_MAX/2;
constexpr lint LINF = LLONG_MAX/2;
constexpr double eps = DBL_EPSILON;
constexpr double PI=3.141592653589793238462643383279;
template<class T>
class prique :public std::priority_queue<T, std::vector<T>, std::greater<T>> {};
template <class T, class U>
inline bool chmax(T& lhs, const U& rhs) {
	if (lhs < rhs) {
		lhs = rhs;
		return 1;
	}
	return 0;
}
template <class T, class U>
inline bool chmin(T& lhs, const U& rhs) {
	if (lhs > rhs) {
		lhs = rhs;
		return 1;
	}
	return 0;
}
inline lint gcd(lint a, lint b) {
	while (b) {
		lint c = a;
		a = b; b = c % b;
	}
	return a;
}
inline lint lcm(lint a, lint b) {
	return a / gcd(a, b) * b;
}
bool isprime(lint n) {
	if (n == 1)return false;
	for (int i = 2; i * i <= n; i++) {
		if (n % i == 0)return false;
	}
	return true;
}
template<typename T>
T mypow(T a, lint b) {
	T res(1);
	while(b){
		if(b&1)res*=a;
		a*=a;
		b>>=1;
	}
	return res;
}
lint modpow(lint a, lint b, lint m) {
	lint res(1);
	while(b){
		if(b&1){
			res*=a;res%=m;
		}
		a*=a;a%=m;
		b>>=1;
	}
	return res;
}
template<typename T>
void printArray(std::vector<T>& vec) {
	rep(i, vec.size()){
		std::cout << vec[i];
		std::cout<<(i==(int)vec.size()-1?"\n":" ");
	}
}
template<typename T>
void printArray(T l, T r) {
	T rprev = std::prev(r);
	for (T i = l; i != rprev; i++) {
		std::cout << *i << " ";
	}
	std::cout << *rprev << std::endl;
}
LP extGcd(lint a,lint b) {
	if(b==0)return {1,0};
	LP s=extGcd(b,a%b);
	std::swap(s.first,s.second);
	s.second-=a/b*s.first;
	return s;
}
LP ChineseRem(const lint& b1,const lint& m1,const lint& b2,const lint& m2) {
	lint p=extGcd(m1,m2).first;
	lint tmp=(b2-b1)*p%m2;
	lint r=(b1+m1*tmp+m1*m2)%(m1*m2);
	return std::make_pair(r,m1*m2);
}
template<typename F>
inline constexpr decltype(auto) lambda_fix(F&& f){
	return [f=std::forward<F>(f)](auto&&... args){
		return f(f,std::forward<decltype(args)>(args)...);
	};
}
#line 3 "/Users/kaage/Desktop/ProgrammingWorkspace/library/data-structure/SegTree.hpp"
template<typename T>
class SegTree {
protected:
	unsigned int n = 1, rank = 0;
	std::vector<T> node;
	T nodee;
	virtual T nodef(const T&, const T&)const = 0;
public:
	SegTree(unsigned int m, T init, T nodee):nodee(nodee) {
		while (n < m) {
			n *= 2;
			rank++;
		}
		node.resize(2 * n, nodee);
		for (unsigned int i = n; i < 2 * n; i++)node[i] = init;
	}
	SegTree(const std::vector<T>& initvec, T nodee):nodee(nodee) {
		unsigned int m = initvec.size();
		while (n < m) {
			n *= 2;
			rank++;
		}
		node.resize(2 * n, nodee);
		for (unsigned int i = n; i < 2 * n; i++) {
			if (i - n < m)node[i] = initvec[i - n];
		}
	}
	virtual void update(int i, T x) {
		i += n;
		node[i] = x;
		while (i != 1) {
			i >>= 1;
			node[i] = nodef(node[2 * i], node[2 * i + 1]);
		}
	}
	virtual T query(int l, int r) {
		l += n; r += n;
		T ls = nodee, rs = nodee;
		while (l < r) {
			if (l & 1) ls = nodef(ls, node[l++]);
			if (r & 1) rs = nodef(node[--r], rs);
			l >>= 1; r >>= 1;
		}
		return nodef(ls, rs);
	}
	virtual T operator[](const int& x) {
		return node[n + x];
	}
	void print() {
		rep(i, n)std::cout << operator[](i) << " ";
		std::cout << std::endl;
	}
};
class RSQ :public SegTree<lint> {
	lint nodef(const lint& lhs,const lint& rhs)const{return lhs+rhs;}
public:
	RSQ(int size, const lint& def = 0) :SegTree<lint>(size, def, 0) {
		for(int i=n-1;i>0;i--)node[i]=nodef(node[i<<1],node[i<<1|1]);
	}
	RSQ(const std::vector<lint>& initvec) :SegTree<lint>(initvec, 0) {
		for(int i=n-1;i>0;i--)node[i]=nodef(node[i<<1],node[i<<1|1]);
	}
};
class RMiQ :public SegTree<lint> {
	lint nodef(const lint& lhs,const lint& rhs)const{return std::min(lhs,rhs);}
public:
	RMiQ(int size, const lint& def = 0) :SegTree<lint>(size, def, LINF) {
		for(int i=n-1;i>0;i--)node[i]=nodef(node[i<<1],node[i<<1|1]);
	}
	RMiQ(const std::vector<lint>& initvec) :SegTree<lint>(initvec, LINF) {
		for(int i=n-1;i>0;i--)node[i]=nodef(node[i<<1],node[i<<1|1]);
	}
};
class RMaQ :public SegTree<lint> {
	lint nodef(const lint& lhs,const lint& rhs)const{return std::max(lhs,rhs);}
public:
	RMaQ(int size, const lint& def = 0) :SegTree<lint>(size, def, -LINF) {
		for(int i=n-1;i>0;i--)node[i]=nodef(node[i<<1],node[i<<1|1]);
	}
	RMaQ(const std::vector<lint>& initvec) :SegTree<lint>(initvec, -LINF) {
		for(int i=n-1;i>0;i--)node[i]=nodef(node[i<<1],node[i<<1|1]);
	}
};
#line 3 "main.cpp"
int H,W,M;
int h[300010],w[300010];
std::vector<int> vec[2][300010];
int main(){
	std::cin>>H>>W>>M;
	rep(i,M){
		std::cin>>h[i]>>w[i];
		h[i]--;w[i]--;
		vec[0][h[i]].emplace_back(w[i]);
		vec[1][w[i]].emplace_back(h[i]);
	}
	lint ans=0;
	RMaQ st(std::max(H,W),0);
	rep(i,W)st.update(i,vec[1][i].size());
	rep(i,H){
		for(int j:vec[0][i])st.update(j,st[j]-1);
		chmax(ans,vec[0][i].size()+st.query(0,std::max(H,W)));
		for(int j:vec[0][i])st.update(j,st[j]+1);
	}
	rep(i,std::max(H,W))st.update(i,0);
	rep(i,H)st.update(i,vec[0][i].size());
	rep(i,W){
		for(int j:vec[1][i])st.update(j,st[j]-1);
		chmax(ans,vec[1][i].size()+st.query(0,std::max(H,W)));
		for(int j:vec[1][i])st.update(j,st[j]+1);
	}
	std::cout<<ans<<std::endl;
	return 0;
}

Measured memory_bytes: 46504