using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Text;
using System.Linq;

using E = System.Linq.Enumerable;
using System.Threading;

internal partial class Solver {
    public void Run() {
        var H = ni();
        var W = ni();
        var M = ni();
        var h = new int[M];
        var w = new int[M];
        var set = new HashSet<(int, int)>();
        for (int i = 0; i < M; i++) {
            h[i] = ni() - 1;
            w[i] = ni() - 1;
        }
        var xHist = Enumerable.Range(0, W).Select(_ => new List<int>()).ToArray();
        var yHist = Enumerable.Range(0, H).Select(_ => new List<int>()).ToArray();
        for (int i = 0; i < M; i++) {
            set.Add((h[i], w[i]));
            xHist[w[i]].Add(i);
            yHist[h[i]].Add(i);
        }
        int curX = 0;
        int curY = 0;
        int ans0 = 0;
        int ans1 = 0;

        for (int i = 0; i < M; i++) {
            var num = xHist[w[i]].Count + yHist[h[i]].Count - 1;
            ans1 = Math.Max(ans1, num);
        }
        bool lastXMoved = true;
        bool found = false;
        Array.Sort(xHist, (v1, v2) => -v1.Count.CompareTo(v2.Count));
        Array.Sort(yHist, (v1, v2) => -v1.Count.CompareTo(v2.Count));
        while (curX < xHist.Length && curY < yHist.Length && xHist[curX].Count > 0 && yHist[curY].Count > 0) {
            var num = xHist[curX].Count + yHist[curY].Count;

            if (lastXMoved) {
                var x = w[xHist[curX][0]];
                for (int i = 0; i <= curY; i++) {
                    var y = h[yHist[i][0]];
                    if (!set.Contains((y, x))) {
                        if (ans0 < num) ans0 = num;
                        found = true;
                        break;
                    }
                }
            } else {
                var y = h[yHist[curY][0]];
                for (int i = 0; i <= curX; i++) {
                    var x = w[xHist[i][0]];
                    if (!set.Contains((y, x))) {
                        if (ans0 < num) ans0 = num;
                        found = true;
                        break;
                    }
                }
            }
            if (found) break;

            if (curX + 1 < xHist.Length && curY + 1 < yHist.Length) {
                var dx = xHist[curX].Count - xHist[curX + 1].Count;
                var dy = yHist[curY].Count - yHist[curY + 1].Count;
                if (dx < dy) {
                    curX++;
                    lastXMoved = true;
                } else {
                    curY++;
                    lastXMoved = false;
                }
            } else if (curX + 1 < xHist.Length) {
                curX++;
                lastXMoved = true;
            } else if (curY + 1 < yHist.Length) {
                curY++;
                lastXMoved = false;
            } else {
                break;
            }
        }
        cout.WriteLine(Math.Max(ans0, ans1));
    }
}

// PREWRITEN CODE BEGINS FROM HERE

static public class StringExtensions {
    static public string JoinToString<T>(this IEnumerable<T> source, string separator = " ") {
        return string.Join(separator, source);
    }
}

internal partial class Solver : Scanner {
    static readonly int? StackSizeInMebiByte = null; //50;
    public static void StartAndJoin(Action action, int maxStackSize) {
        var thread = new Thread(new ThreadStart(action), maxStackSize);
        thread.Start();
        thread.Join();
    }

    public static void Main() {
#if LOCAL
        byte[] inputBuffer = new byte[1000000];
        var inputStream = Console.OpenStandardInput(inputBuffer.Length);
        using (var reader = new StreamReader(inputStream, Console.InputEncoding, false, inputBuffer.Length)) {
            Console.SetIn(reader);
            new Solver(Console.In, Console.Out).Run();
        }
#else
        Console.SetOut(new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false });
        if (StackSizeInMebiByte.HasValue) {
            StartAndJoin(() => new Solver(Console.In, Console.Out).Run(), StackSizeInMebiByte.Value * 1024 * 1024);
        } else {
            new Solver(Console.In, Console.Out).Run();
        }
        Console.Out.Flush();
#endif
    }

#pragma warning disable IDE0052
    private readonly TextReader cin;
    private readonly TextWriter cout;
    private readonly TextWriter cerr;
#pragma warning restore IDE0052

    public Solver(TextReader reader, TextWriter writer)
        : base(reader) {
        cin = reader;
        cout = writer;
        cerr = Console.Error;
    }

    public Solver(string input, TextWriter writer)
        : this(new StringReader(input), writer) {
    }

#pragma warning disable IDE1006
#pragma warning disable IDE0051
    private int ni() { return NextInt(); }
    private int[] ni(int n) { return NextIntArray(n); }
    private long nl() { return NextLong(); }
    private long[] nl(int n) { return NextLongArray(n); }
    private double nd() { return NextDouble(); }
    private double[] nd(int n) { return NextDoubleArray(n); }
    private string ns() { return Next(); }
    private string[] ns(int n) { return NextArray(n); }
#pragma warning restore IDE1006
#pragma warning restore IDE0051
}

#if DEBUG
internal static class LinqPadExtension {
    public static string TextDump<T>(this T obj) {
        if (obj is IEnumerable) return (obj as IEnumerable).Cast<object>().JoinToString().Dump();
        else return obj.ToString().Dump();
    }
    public static T Dump<T>(this T obj) {
        return LINQPad.Extensions.Dump(obj);
    }
}
#endif

public class Scanner {
    private readonly TextReader Reader;
    private readonly CultureInfo ci = CultureInfo.InvariantCulture;

    private readonly char[] buffer = new char[2 * 1024];
    private int cursor = 0, length = 0;
    private string Token;
    private readonly StringBuilder sb = new StringBuilder(1024);

    public Scanner()
        : this(Console.In) {
    }

    public Scanner(TextReader reader) {
        Reader = reader;
    }

    public int NextInt() { return checked((int)NextLong()); }
    public long NextLong() {
        var s = Next();
        long r = 0;
        int i = 0;
        bool negative = false;
        if (s[i] == '-') {
            negative = true;
            i++;
        }
        for (; i < s.Length; i++) {
            r = r * 10 + (s[i] - '0');
#if DEBUG
            if (!char.IsDigit(s[i])) throw new FormatException();
#endif
        }
        return negative ? -r : r;
    }
    public double NextDouble() { return double.Parse(Next(), ci); }
    public string[] NextArray(int size) {
        string[] array = new string[size];
        for (int i = 0; i < size; i++) {
            array[i] = Next();
        }

        return array;
    }
    public int[] NextIntArray(int size) {
        int[] array = new int[size];
        for (int i = 0; i < size; i++) {
            array[i] = NextInt();
        }

        return array;
    }

    public long[] NextLongArray(int size) {
        long[] array = new long[size];
        for (int i = 0; i < size; i++) {
            array[i] = NextLong();
        }

        return array;
    }

    public double[] NextDoubleArray(int size) {
        double[] array = new double[size];
        for (int i = 0; i < size; i++) {
            array[i] = NextDouble();
        }

        return array;
    }

    public string Next() {
        if (Token == null) {
            if (!StockToken()) {
                throw new Exception();
            }
        }
        var token = Token;
        Token = null;
        return token;
    }

    public bool HasNext() {
        if (Token != null) {
            return true;
        }

        return StockToken();
    }

    private bool StockToken() {
        while (true) {
            sb.Clear();
            while (true) {
                if (cursor >= length) {
                    cursor = 0;
                    if ((length = Reader.Read(buffer, 0, buffer.Length)) <= 0) {
                        break;
                    }
                }
                var c = buffer[cursor++];
                if (33 <= c && c <= 126) {
                    sb.Append(c);
                } else {
                    if (sb.Length > 0) break;
                }
            }

            if (sb.Length > 0) {
                Token = sb.ToString();
                return true;
            }

            return false;
        }
    }
}

Measured memory_bytes: 89716