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

#define rep(i,n) for(int i = 0; i < (int)n; i++)
#define FOR(n) for(int i = 0; i < (int)n; i++)
#define repi(i,a,b) for(int i = (int)a; i < (int)b; i++)
#define pb push_back
#define m0(x) memset(x,0,sizeof(x))
#define fill(x,y) memset(x,y,sizeof(x))
#define bg begin()
#define ed end()
#define all(x) x.bg,x.ed
#define vi vector<int>
#define vvi vector<vi>
#define vll vector<ll>
#define vvll vector<vll>
#define vs vector<string>
#define vvs vector<vs>
#define vc vector<char>
#define vvc vector<vc>
#define pii pair<int,int>
#define pllll pair<ll,ll>
#define vpii vector<pair<int,int>>
#define vpllll vector<pair<ll,ll>>
#define vpis vector<pair<int,string>>
#define vplls vector<pair<ll, string>>
#define vpsi vector<pair<string, int>>
#define vpsll vector<pair<string, ll>>

#define int ll

using ll = long long;
using ld = long double;
using ull = unsigned long long;

void print_vec(vector<int> &a) {
    for(int i = 0; i < (int)a.size(); i++) {
        cout << a[i];
        if(i != a.size() - 1) cout << " ";
    }
    cout << "\n";
}

const ll INF = 1e15;
const ld pi = 3.1415926535897932384626433832795028;
const ll mod = 1e9 + 7;
int dx[] = {-1, 0, 1, 0, -1, -1, 1, 1};
int dy[] = {0, -1, 0, 1, -1, 1, -1, 1};

void solve() {
    int n, m, q;
    cin >> n >> m >> q;
    vi x(q), y(q);
    vvi grid(n, vi(m, 0));
    FOR(q) {
        cin >> x[i] >> y[i];
        x[i]--;
        y[i]--;
        grid[x[i]][y[i]]++;
    }
    vvi gridn = grid;
    repi(i, 1, n) {
        rep(j, m) {
            grid[i][j] += grid[i - 1][j];
            if(grid[i][j] > 1) grid[i][j] = 1;
        }
    }
    repi(j, 1, m) {
        rep(i, n) {
            grid[i][j] += grid[i][j - 1];
        }
    }
    repi(j, 1, m) {
        rep(i, n) {
            gridn[i][j] += gridn[i][j - 1];
            if(gridn[i][j] > 1) gridn[i][j] = 1;
        }
    }
    repi(i, 1, n) {
        rep(j, m) {
            gridn[i][j] += gridn[i - 1][j];
        }
    }
    int ans = 0;
    FOR(q) {
        ans = max(ans, min(grid[x[i]][y[i]], gridn[x[i]][y[i]]));
    }
    cout << ans << endl;
}

/*
// D
void solve() {
    int n;
    cin >> n;
    string s;
    cin >> s;
    s = "-" + s;
    // target 
    string t = "+yukicoder";
    int m = t.size();
    vvi dp(n + 1, vi(m, 0));
    rep(i, n + 1) {
        rep(j, m) {
            if(j == 0) dp[i][j] = 1;
            else if(i == 0) dp[i][j] = 0;
            else if(s[i] != t[j]) dp[i][j] = dp[i - 1][j] % mod;
            else dp[i][j] = (dp[i - 1][j] + dp[i - 1][j - 1]) % mod;
        }
    }
    int ans = dp[n][m - 1];
    repi(i, 1, m) {
        string tmp = t;
        t[i] = '?';
        dp = vector<vector<int>>(n + 1, vector<int>(m, 0));
        rep(i, n + 1) {
            rep(j, m) {
                if(j == 0) dp[i][j] = 1;
                else if(i == 0) dp[i][j] = 0;
                else if(s[i] != t[j]) dp[i][j] = dp[i - 1][j] % mod;
                else dp[i][j] = (dp[i - 1][j] + dp[i - 1][j - 1]) % mod;
            }
        }
        t = tmp;
        ans += dp[n][m - 1] % mod;
        ans %= mod;
    }
    cout << ans % mod << endl;
}
*/

/*
// C
void solve() {
    int n, w;
    cin >> n >> w;
    vi a(n);
    int zeroes = 0;
    FOR(n) {
        cin >> a[i];
        if(a[i] == 0) zeroes++;
    }
    map<int, int> mp;
    repi(i, 1, 1 << n) {
        int now = 0;
        vector<int> ids;
        rep(j, n) {
            if(i & 1 << j) {
                now += a[j];
                ids.push_back(j);
            }
        }
        map<int, int> tmp;
        rep(j, 1 << ids.size()) {
            int v = 0;
            rep(k, ids.size()) {
                if(j & 1 << k) {
                    v += a[ids[k]] / 2;
                }
            }
            tmp[now - v]++;
        }
        for(auto e : tmp) {
            mp[e.first]++;
        }
    }
    cout << mp[w] << endl;
    /*
    map<int, int> mp;
    rep(i, 1 << n) {
        int now = 0;
        rep(j, n) {
            if(i >> j & 1) {
                now += a[j];
            }
        }
        mp[now]++;
    }
    if(mp[w] > 0) {
        cout << 
    }
    rep(i, 1 << n) {
        int now = 0;
        rep(j, n) {
            if(i >> j & 1) {
                now += a[j] / 2;
            }
        }
        if(mp[])
    }
    
}
*/

signed main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    solve();
    return 0;
}