//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
using db = double;
using ld = long double;
template<typename T> using V = vector<T>;
template<typename T> using VV = vector<vector<T>>;
#define fs first
#define sc second
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
#define all(v) (v).begin(),(v).end()
#define siz(v) (ll)(v).size()
#define rep(i,a,n) for(ll i=a;i<(ll)(n);++i)
#define repr(i,a,n) for(ll i=n-1;(ll)a<=i;--i)
#define ENDL '\n'
typedef pair<int,int> Pi;
typedef pair<ll,ll> PL;
constexpr ll mod = 1000000007; // 998244353;
constexpr ll INF = 1000000099;
constexpr ll LINF = (ll)(1e18 +99);
const ld PI = acos((ld)-1);
const vector<ll> dx={-1,1,0,0},dy={0,0,-1,1};
template<typename T,typename U> inline bool chmin(T& t, const U& u){if(t>u){t=u;return 1;}return 0;}
template<typename T,typename U> inline bool chmax(T& t, const U& u){if(t<u){t=u;return 1;}return 0;}
template<typename T> inline T gcd(T a,T b){return b?gcd(b,a%b):a;}

template<typename T,typename Y> inline T mpow(T a, Y n) {
  T res = 1;
  for(;n;n>>=1) {
    if (n & 1) res = res * a;
    a = a * a;
  }
  return res;
}

template<typename T,typename Y>
ostream& operator<<(ostream& os,const pair<T,Y>& p){
  return os<<"{"<<p.fs<<","<<p.sc<<"}";
}
template<typename T> ostream& operator<<(ostream& os,const V<T>& v){
  os<<"{";
  for(auto e:v)os<<e<<",";
  return os<<"}";
}
template<typename ...Args>
void debug(Args&... args){
  for(auto const& x:{args...}){
    cerr<<x<<' ';
  }
  cerr<<ENDL;
}

template<typename T,typename Y,T(F_up)(T,T),Y(F_gt)(T,Y)>
struct BUPSegTree{
    int sz,ex;
    T ini_d;
    vector<T> dat;

    BUPSegTree(vector<T> init,T _ini_d) : ini_d(_ini_d){
        int n=(int)(init.size());
        ex=1;
        while((1<<ex) < n)ex++;
        sz=(1<<ex);
        dat=vector<T>(2*sz,ini_d);
        for (int i = 0; i < n; ++i) dat[sz + i] = init[i];
        for (int i = sz - 1; i > 0; --i) dat[i] = F_up(dat[2*i],dat[2*i+1]);
    }

    void up_q(int p,T x){
        for(dat[p+=sz]+=x;p>1;p>>=1){//
            dat[p>>1]=F_up(dat[p],dat[p^1]);
        }
    }

    T get_q(int l,int r){//[l,r)
        T res=ini_d;
        for(l+=sz,r+=sz;l<r;l>>=1,r>>=1){
            if(l&1){
                res=F_gt(res,dat[l]);
                ++l;
            }
            if(r&1){
                --r;
                res=F_gt(res,dat[r]);
            }
        }
        return res;
    }
};
//0-indexedと思って渡してよい
ll my_max(ll a,ll b){return max(a,b);}

signed main(){
  cin.tie(0);cerr.tie(0);ios::sync_with_stdio(false);
  cout<<fixed<<setprecision(20);
  ll h,w,m;cin>>h>>w>>m;

  BUPSegTree<ll,ll,my_max,my_max> seg(V<ll>(w+2,0),0);
  VV<ll> gs(h+2,V<ll>(0));

  rep(i,0,m){
    ll g,r;cin>>g>>r;
    --g;--r;
    gs[g].eb(r);
    seg.up_q(r,1);
  }


  ll ans=0;
  rep(i,0,h){
    ll tmp=siz(gs[i]);

    rep(j,0,siz(gs[i])){
      seg.up_q(gs[i][j],-1);
    }

    chmax(ans,tmp+seg.get_q(0,w));

    rep(j,0,siz(gs[i])){
      seg.up_q(gs[i][j],1);
    }
  }

  cout<<ans<<ENDL;
}
//! ( . _ . ) ! 
//CHECK overflow,vector_size,what to output?

Measured memory_bytes: 27920