#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<long long> VL;
typedef vector<vector<long long>> VVL;
typedef pair<ll,ll> P;
typedef tuple<int,int,int> tpl;

#define ALL(a)  (a).begin(),(a).end()
#define SORT(c) sort((c).begin(),(c).end())
#define REVERSE(c) reverse((c).begin(),(c).end())
#define EXIST(m,v) (m).find((v)) != (m).end()
#define LB(a,x) lower_bound((a).begin(), (a).end(), x) - (a).begin()
#define UB(a,x) upper_bound((a).begin(), (a).end(), x) - (a).begin()

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define RFOR(i,a,b) for(int i=(a)-1;i>=(b);--i)
#define RREP(i,n) RFOR(i,n,0)

#define en "\n"

constexpr double EPS = 1e-9;
constexpr double PI  = 3.1415926535897932;
constexpr int INF = 2147483647;
constexpr long long LINF = 1LL<<60;
constexpr long long MOD = 1000000007; // 998244353;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }

template<typename T>
struct SegmentTree {
	typedef function<T(T,T)> F;
    typedef function<T(T,T)> G;
    int n;
    F f;
    G g;
    T e;

    vector<T> val;

    SegmentTree(vector<T> a, F f_, G g_, T e):
        f(f_), g(g_), e(e){
            int sz = a.size();
            n = 1;

            while (n < sz) n <<= 1;
            val.resize(2 * n - 1, e);
            for (int i = 0; i < sz; i++) val[i + n - 1] = a[i];
            for (int i = n - 2; i >= 0; i--) val[i] = f(val[i * 2 + 1], val[i * 2 + 2]);
        }
    
        SegmentTree() {}

        void update(int pos, T v) {
            // 0-indexed
            int k = pos + n - 1;
            val[k] = g(val[k], v);
            while (k > 0) {
                k = (k - 1) / 2;
                val[k] = f(val[k * 2 + 1], val[k * 2 + 2]);
            }
        }

        T get(int pos) {
            // 0-indexed
            int k = pos + n - 1;
            return val[k];
        }

        T query(int a, int b, int k = 0, int l = 0, int r = -1) {
            // 0-indexed
            // [a,b)に対してquery
            if (r < 0) r = n;
            if (r <= a || b <= l) return e;
            if (a <= l && r <= b) return val[k];
            T lv = query(a, b, k * 2 + 1, l, (l + r) / 2);
            T rv = query(a, b, k * 2 + 2, (l + r) / 2, r);
            return f(lv, rv);
        }
};

ll f(ll a, ll b){
    return max(a,b);
}
ll g(ll a, ll b){
    return a+b;
}

void Main(){
    ll H,W,M; cin >> H >> W >> M;
    VVI h(H), w(W);
    VL hh(H,0), ww(W,0);

    REP(i,M){
        ll s,t; cin >> s >> t; s--; t--;
        h[s].push_back(t);
        w[t].push_back(s);
        hh[s]++; ww[t]++;
    }

    ll ans = 0;
    
    SegmentTree<ll> st1(hh,f,g,-INF), st2(ww,f,g,-INF);
    REP(i,H){
        if(h[i].empty()) continue;
        for(int t : h[i]){
            st2.update(t,-1);
        }
        ll mx = st2.query(0,W);
        chmax(ans, hh[i]+mx);
        for(int t : h[i]){
            st2.update(t,1);
        }
    }

    REP(i,W){
        if(w[i].empty()) continue;
        for(int t : w[i]){
            st1.update(t,-1);
        }
        ll mx = st1.query(0,H);
        chmax(ans, ww[i]+mx);
        for(int t : w[i]){
            st1.update(t,1);
        }
    }

    cout << ans << en;
    return;
}

int main(void){
    cin.tie(0);cout.tie(0);ios_base::sync_with_stdio(0);cout<<fixed<<setprecision(15);
    int t=1; //cin>>t;
    REP(_,t) Main();
    return 0;
}

Measured memory_bytes: 59360