using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    static int[][] NArr(long n) => Enumerable.Repeat(0, (int)n).Select(_ => NList).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (n, m, q) = (c[0], c[1], c[2]);
        var map = NArr(q);
        WriteLine(Pair(n, m, q, map));
    }
    static int Pair(int n, int m, int q, int[][] map)
    {
        var ex = new bool[n, m];
        foreach (var pair in map) ex[pair[0] - 1, pair[1] - 1] = true;
        var dp = new int[m];
        for (var i = 0; i < n; ++i)
        {
            var ndp = (int[]) dp.Clone();
            for (var j = 0; j < m; ++j) if (ex[i, j])
            {
                if (j == 0) ndp[j] = 1;
                else ndp[j] = dp[j - 1] + 1;
            }
            for (var j = 1; j < m; ++j) ndp[j] = Math.Max(ndp[j - 1], ndp[j]);
            dp = ndp;
        }
        return dp[^1];
    }
}