/* #region Head */

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

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pll = pair<ll, ll>;
template <class T> using vc = vector<T>;
template <class T> using vvc = vc<vc<T>>;
using vll = vc<ll>;
using vvll = vvc<ll>;
using vld = vc<ld>;
using vvld = vvc<ld>;
using vs = vc<string>;
using vvs = vvc<string>;
template <class T, class U> using um = unordered_map<T, U>;
template <class T> using pq = priority_queue<T>;
template <class T> using pqa = priority_queue<T, vc<T>, greater<T>>;
template <class T> using us = unordered_set<T>;

#define REP(i, m, n) for (ll i = (m), i##_len = (ll)(n); i < i##_len; ++(i))
#define REPM(i, m, n) for (ll i = (m), i##_max = (ll)(n); i <= i##_max; ++(i))
#define REPR(i, m, n) for (ll i = (m), i##_min = (ll)(n); i >= i##_min; --(i))
#define REPD(i, m, n, d) for (ll i = (m), i##_len = (ll)(n); i < i##_len; i += (d))
#define REPMD(i, m, n, d) for (ll i = (m), i##_max = (ll)(n); i <= i##_max; i += (d))
#define REPI(itr, ds) for (auto itr = ds.begin(); itr != ds.end(); itr++)
#define ALL(x) begin(x), end(x)
#define SIZE(x) ((ll)(x).size())
#define PERM(c)                                                                                                        \
    sort(ALL(c));                                                                                                      \
    for (bool c##p = 1; c##p; c##p = next_permutation(ALL(c)))
#define UNIQ(v) v.erase(unique(ALL(v)), v.end());

#define endl '\n'
#define sqrt sqrtl
#define floor floorl
#define log2 log2l

constexpr ll INF = 1'010'000'000'000'000'017LL;
constexpr ll MOD = 1'000'000'007LL; // 1e9 + 7
constexpr ld EPS = 1e-12;
constexpr ld PI = 3.14159265358979323846;

template <typename T> istream &operator>>(istream &is, vc<T> &vec) { // vector 入力
    for (T &x : vec) is >> x;
    return is;
}
template <typename T> ostream &operator<<(ostream &os, vc<T> &vec) { // vector 出力 (for dump)
    os << "{";
    REP(i, 0, SIZE(vec)) os << vec[i] << (i == i_len - 1 ? "" : ", ");
    os << "}";
    return os;
}
template <typename T> ostream &operator>>(ostream &os, vc<T> &vec) { // vector 出力 (inline)
    REP(i, 0, SIZE(vec)) os << vec[i] << (i == i_len - 1 ? "\n" : " ");
    return os;
}

template <typename T, typename U> istream &operator>>(istream &is, pair<T, U> &pair_var) { // pair 入力
    is >> pair_var.first >> pair_var.second;
    return is;
}
template <typename T, typename U> ostream &operator<<(ostream &os, pair<T, U> &pair_var) { // pair 出力
    os << "(" << pair_var.first << ", " << pair_var.second << ")";
    return os;
}

// map, um, set, us 出力
template <class T> ostream &out_iter(ostream &os, T &map_var) {
    os << "{";
    REPI(itr, map_var) {
        os << *itr;
        auto itrcp = itr;
        if (++itrcp != map_var.end()) os << ", ";
    }
    return os << "}";
}
template <typename T, typename U> ostream &operator<<(ostream &os, map<T, U> &map_var) { return out_iter(os, map_var); }
template <typename T, typename U> ostream &operator<<(ostream &os, um<T, U> &map_var) {
    os << "{";
    REPI(itr, map_var) {
        auto [key, value] = *itr;
        os << "(" << key << ", " << value << ")";
        auto itrcp = itr;
        if (++itrcp != map_var.end()) os << ", ";
    }
    os << "}";
    return os;
}
template <typename T> ostream &operator<<(ostream &os, set<T> &set_var) { return out_iter(os, set_var); }
template <typename T> ostream &operator<<(ostream &os, us<T> &set_var) { return out_iter(os, set_var); }
template <typename T> ostream &operator<<(ostream &os, pq<T> &pq_var) {
    pq<T> pq_cp(pq_var);
    os << "{";
    if (!pq_cp.empty()) {
        os << pq_cp.top(), pq_cp.pop();
        while (!pq_cp.empty()) os << ", " << pq_cp.top(), pq_cp.pop();
    }
    return os << "}";
}

// dump
#define DUMPOUT cerr
void dump_func() { DUMPOUT << endl; }
template <class Head, class... Tail> void dump_func(Head &&head, Tail &&... tail) {
    DUMPOUT << head;
    if (sizeof...(Tail) > 0) DUMPOUT << ", ";
    dump_func(move(tail)...);
}

// chmax (更新「される」かもしれない値が前)
template <typename T, typename U, typename Comp = less<>> bool chmax(T &xmax, const U &x, Comp comp = {}) {
    if (comp(xmax, x)) {
        xmax = x;
        return true;
    }
    return false;
}

// chmin (更新「される」かもしれない値が前)
template <typename T, typename U, typename Comp = less<>> bool chmin(T &xmin, const U &x, Comp comp = {}) {
    if (comp(x, xmin)) {
        xmin = x;
        return true;
    }
    return false;
}

// ローカル用
#define DEBUG_

#ifdef DEBUG_
#define DEB
#define dump(...)                                                                                                      \
    DUMPOUT << "  " << string(#__VA_ARGS__) << ": "                                                                    \
            << "[" << to_string(__LINE__) << ":" << __FUNCTION__ << "]" << endl                                        \
            << "    ",                                                                                                 \
        dump_func(__VA_ARGS__)
#else
#define DEB if (false)
#define dump(...)
#endif

struct AtCoderInitialize {
    static constexpr int IOS_PREC = 15;
    static constexpr bool AUTOFLUSH = false;
    AtCoderInitialize() {
        ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
        cout << fixed << setprecision(IOS_PREC);
        if (AUTOFLUSH) cout << unitbuf;
    }
} ATCODER_INITIALIZE;

void Yn(bool p) { cout << (p ? "Yes" : "No") << endl; }
void YN(bool p) { cout << (p ? "YES" : "NO") << endl; }

/* #endregion */

/* #region CoordCompress1D */

// 1次元座圧
class CoordCompress1D {
    um<ll, ll> coord2zipped; // キーが座標値
    vll zipped2coord;        // 各要素が座標値
    ll sz;

  public:
    CoordCompress1D() {}
    CoordCompress1D(vll coords) {
        sort(ALL(coords));
        UNIQ(coords);
        sz = SIZE(coords);
        zipped2coord = coords;
        REP(i, 0, sz) coord2zipped[coords[i]] = i;
    }
    // 座標の圧縮（コンストラクタに与えた座標限定）
    ll zip(ll coord) { return coord2zipped[coord]; }
    ll unzip(ll zipped) { return zipped2coord[zipped]; }

    // coord 以上の最小の座標値を返す
    ll coord_geq(ll coord) {
        auto it = lower_bound(ALL(zipped2coord), coord);
        if (it != zipped2coord.end()) return *it;
        return INF;
    }

    // coord より大きいの最小の座標値を返す
    ll coord_gt(ll coord) {
        auto it = upper_bound(ALL(zipped2coord), coord);
        if (it != zipped2coord.end()) return *it;
        return INF;
    }

    // coord 以下の最小の座標値を返す
    ll coord_leq(ll coord) {
        auto rit = lower_bound(zipped2coord.rbegin(), zipped2coord.rend(), coord,
                               [](ll const lhs, ll const rhs) { return lhs > rhs; });
        if (rit != zipped2coord.rend()) return *rit;
        return -INF;
    }

    // coord 未満の最小の座標値を返す
    ll coord_lt(ll coord) {
        auto rit = upper_bound(zipped2coord.rbegin(), zipped2coord.rend(), coord,
                               [](ll const lhs, ll const rhs) { return lhs > rhs; });
        if (rit != zipped2coord.rend()) return *rit;
        return -INF;
    }

    ll size() { return sz; }
};

/* #endregion */

/* #region CoordCompress2D */

// 2次元座圧
// このクラス自体は区画を管理するだけで，塗られているかどうかは管理しないので，外側で考える．
class CoordCompress2D {
    CoordCompress1D axis_x, axis_y;

    void add_space(vll &coords) {
        ll _sz = SIZE(coords);
        ll mi = *min_element(ALL(coords));
        coords.resize(_sz * 2 + 1);
        REP(i, 0, _sz) coords[_sz + i] = coords[i] + 1; // 全座標について，+1したところもキープ
        coords[2 * _sz] = mi - 1;                       // 最小の座標は -1 したところもキープ
    }

  public:
    CoordCompress2D(vll coordsX, vll coordsY) {
        add_space(coordsX), add_space(coordsY);
        axis_x = CoordCompress1D(coordsX);
        axis_y = CoordCompress1D(coordsY);
    }
    pll zip(ll coord_x, ll coord_y) { return {axis_x.zip(coord_x), axis_y.zip(coord_y)}; }
    pll unzip(ll zipped_x, ll zipped_y) { return {axis_x.unzip(zipped_x), axis_y.unzip(zipped_y)}; }

    ll area(ll zipped_x, ll zipped_y) {
        if (zipped_x <= 0 || zipped_y <= 0 || zipped_x + 1 >= axis_x.size() || zipped_y + 1 >= axis_y.size()) {
            return INF;
        }
        ll dx = axis_x.unzip(zipped_x + 1) - axis_x.unzip(zipped_x);
        ll dy = axis_y.unzip(zipped_y + 1) - axis_y.unzip(zipped_y);
        return dx * dy;
    }

    pll coords_leq(ll coord_x, ll coord_y) { return {axis_x.coord_leq(coord_x), axis_y.coord_leq(coord_y)}; }
};

/* #endregion */

// Problem
void solve() {
    ll H, W, m;
    cin >> H >> W >> m;
    vll h(m), w(m);
    REP(i, 0, m) {
        cin >> h[i] >> w[i];
        --h[i], --w[i];
    }

    // CoordCompress2D cc(w, h);

    // vll zipped_h(m), zipped_w(m);
    // REP(i, 0, m) {
    //     auto [zipped_wi, zipped_hi] = cc.zip(w[i], h[i]); //
    //     zipped_h[i] = zipped_hi;
    //     zipped_w[i] = zipped_wi;
    // }
    // dump(zipped_h, zipped_w);
    set<pll> coords;
    REP(i, 0, m) { coords.emplace(h[i], w[i]); }

    vll acc_h(H, 0);
    vll acc_w(W, 0);
    REP(i, 0, m) {
        acc_h[h[i]]++;
        acc_w[w[i]]++;
    }
    // dump(acc_h, acc_w);
    auto ma_h = max_element(ALL(acc_h));
    auto ma_w = max_element(ALL(acc_w));
    ll hmi = ma_h - acc_h.begin();
    ll wmi = ma_w - acc_w.begin();

    // ll ret = (*ma_h) + (*ma_w);
    // {
    //     pll needle = {hmi, wmi};
    //     if (coords.count(needle)) ret--;
    // }
    // REP(i, 0, m) {
    //     ll x = acc_h[i] + acc_w[i] - 1;
    //     chmax(ret, x);
    // }
    // cout << ret << endl;

    ll ret = 0;
    // hmi を固定で横方向に走査する
    REP(j, 0, W) {
        ll x = *ma_h + acc_w[j];
        pll needle = {hmi, j};
        if (coords.count(needle)) --x;
        chmax(ret, x);
    }
    // wmi を固定で縦方向に走査する
    REP(i, 0, H) {
        ll x = *ma_w + acc_h[i];
        pll needle = {i, wmi};
        if (coords.count(needle)) --x;
        chmax(ret, x);
    }
    cout << ret << endl;
}

// entry point
int main() {
    solve();
    return 0;
}


Measured memory_bytes: 31420