//header{{{
#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>

#include <boost/sort/spreadsort/spreadsort.hpp>
#include <boost/multiprecision/cpp_int.hpp>
#include <boost/multiprecision/cpp_dec_float.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/dijkstra_shortest_paths.hpp>
//#include <boost/graph/graph_utility.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/tag_and_trait.hpp>
#include <ext/pb_ds/trie_policy.hpp>

using namespace __gnu_pbds;
using namespace std;
//using namespace boost::multiprecision;
//using namespace boost::math;

typedef boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS,
        boost::no_property, boost::property<boost::edge_weight_t, int> > Graph;

#define rep(i,n) for(int i=0;i<(n);++i)
#define reps(i,n) for(int i=1;i<=(n);++i)
#define all(x) (x).begin(),(x).end()
#define Fixed fixed << setprecision(12)
#define bsort boost::sort::spreadsort::spreadsort
#define int int_fast64_t
using pii = pair<int,int>;

constexpr int INF  = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr int mod1 = 1e9+7; 
constexpr int mod2 = 998244353;
template <class Func>

class FixPoint : Func {
public:
    explicit constexpr FixPoint(Func&& f) noexcept : Func(forward<Func>(f)) {}
 
    template <class... Args>
    constexpr decltype(auto) operator()(Args&&... args) const {
        return Func::operator()(*this, std::forward<Args>(args)...);
    }
};
 
template <class Func>
static inline constexpr decltype(auto) makeFixPoint(Func&& f) noexcept {
    return FixPoint<Func>{forward<Func>(f)};
}

template <class A, class B> inline bool chmax(A &a, const B &b) { return b > a && (a = b, true); }
template <class A, class B> inline bool chmin(A &a, const B &b) { return b < a && (a = b, true); }

template <class T> using min_heap = priority_queue<T,vector<T>,greater<T> >;
template <class T> using max_heap = priority_queue<T>;
template <class A, class B> using umap = unordered_map<A,B>;

template <typename T> using Set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template <typename K, typename V> using Umap = gp_hash_table<K, V>;
using Trie = trie<string, null_type, trie_string_access_traits<>, pat_trie_tag, trie_prefix_search_node_update>;
  
inline int square(int a){ return a * a;}
inline int updiv(int a,int b){ return (a + b - 1) / b; }

constexpr int dx[] = {1,0,-1,0,1,1,-1,-1};
constexpr int dy[] = {0,-1,0,1,1,-1,-1,1};

constexpr int dxw[] = {-2, -1, 0, 1, 2, -2, -1, 1, 2, -2, 2, -2, -1, 1, 2, -2, -1, 0, 1, -2};
constexpr int dyw[] = {-2, -2, -2, -2, -2, -1, -1, -1, -1, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 2};

struct negrightshift {
    inline int operator() (const int &x, const unsigned offset) {
        return -(x >> offset);
    }
};
//}}}

template< typename Monoid >
struct SegmentTree {
    using F = function< Monoid(Monoid, Monoid) >;

    int sz;
    vector< Monoid > seg;

    const F f;
    const Monoid M1;

    SegmentTree(int n, const F f, const Monoid &M1) : f(f), M1(M1) {
        sz = 1;
        while(sz < n) sz <<= 1;
        seg.assign(2 * sz, M1);
    }

    void set(int k, const Monoid &x) {
        seg[k + sz] = x;
    }

    void build() {
        for(int k = sz - 1; k > 0; k--) {
            seg[k] = f(seg[2 * k + 0], seg[2 * k + 1]);
        }
    }

    void update(int k, const Monoid &x) {
        k += sz;
        seg[k] = x;
        while(k >>= 1) {
            seg[k] = f(seg[2 * k + 0], seg[2 * k + 1]);
        }
    }

    Monoid query(int a, int b) {
        Monoid L = M1, R = M1;
        for(a += sz, b += sz; a < b; a >>= 1, b >>= 1) {
            if(a & 1) L = f(L, seg[a++]);
            if(b & 1) R = f(seg[--b], R);
        }
        return f(L, R);
    }

    Monoid operator[](const int &k) const {
        return seg[k + sz];
    }

    template< typename C >
    int find_subtree(int a, const C &check, Monoid &M, bool type) {
        while(a < sz) {
            Monoid nxt = type ? f(seg[2 * a + type], M) : f(M, seg[2 * a + type]);
            if(check(nxt)) a = 2 * a + type;
            else M = nxt, a = 2 * a + 1 - type;
        }
        return a - sz;
    }

    template< typename C >
    int find_first(int a, const C &check) {
        Monoid L = M1;
        if(a <= 0) {
            if(check(f(L, seg[1]))) return find_subtree(1, check, L, false);
            return -1;
        }
        int b = sz;
        for(a += sz, b += sz; a < b; a >>= 1, b >>= 1) {
            if(a & 1) {
                Monoid nxt = f(L, seg[a]);
                if(check(nxt)) return find_subtree(a, check, L, false);
                L = nxt;
                ++a;
            }
        }
        return -1;
    }

    template< typename C >
    int find_last(int b, const C &check) {
        Monoid R = M1;
        if(b >= sz) {
            if(check(f(seg[1], R))) return find_subtree(1, check, R, true);
            return -1;
        }
        int a = sz;
        for(b += sz; a < b; a >>= 1, b >>= 1) {
            if(b & 1) {
                Monoid nxt = f(seg[--b], R);
                if(check(nxt)) return find_subtree(b, check, R, true);
                R = nxt;
            }
        }
        return -1;
    }
};

signed main(){
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
    cout.setf(ios_base::fixed);
    cout.precision(10);

    int h, w, m;
    cin >> h >> w >> m;

    vector<int> y(m), x(m);   
    vector<int> y_cnt(h+1), x_cnt(w+1);
    vector<vector<int> > y_xs(h+1);

    SegmentTree<int> seg(3e5+5, [](int a, int b){ return max(a, b);}, 0);

    rep(i,m){
        cin >> y[i] >> x[i];
        ++y_cnt[y[i]];
        ++x_cnt[x[i]];
        y_xs[y[i]].emplace_back(x[i]);
        seg.set(x[i], seg[x[i]] + 1);
    }

    seg.build();

    reps(i, h){
        sort(all(y_xs[i])); 
    }

    int res = 0;

    reps(i,h){
        int siz = y_xs[i].size();
        int prex = 0;
        rep(j,siz){
            chmax(res, y_cnt[i] + seg.query(prex+1, y_xs[i][j]));
            chmax(res, y_cnt[i] + x_cnt[y_xs[i][j]] - 1);
            prex = y_xs[i][j];
        }
        chmax(res, y_cnt[i] + seg.query(prex + 1, w+1));
    }

    cout << res << '\n';

    return 0;
}

Measured memory_bytes: 37232