import java.io.BufferedReader;
import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.ListIterator;
import java.util.Map.Entry;

import java.util.PriorityQueue;
import java.util.Random;
import java.util.StringTokenizer;
import java.util.TreeMap;
import java.util.TreeSet;


public class Main {
	
	public static class SegTree{
		int n;
		long[] dat;

		public SegTree(int n_) {
			int n = 1;
			while(n < n_){ n *= 2; }

			this.n = n;
			dat = new long[this.n * 2 - 1];
			for(int i = 0; i < this.n * 2 - 1 ; i++){
				dat[i] = 0;
			}
		}
		
		public long calc(long fst, long snd){ return Math.max(fst, snd); }
		
		public void add(int k, long a){
			k += n - 1;
			dat[k] += a;

			while(k > 0){
				k = (k - 1) / 2;
				dat[k] = calc(dat[k * 2 + 1], dat[k * 2 + 2]);
			}
		}

		public long query(int a, int b, int k, int l, int r){
			if(r <= a || b <= l){
				return 0;
			}else if(a <= l && r <= b){
				return dat[k];
			}else {
				return calc(query(a, b, k * 2 + 1, l, (l + r) / 2), query(a, b, k * 2 + 2 , (l + r) / 2, r));
			}
		}

		public long query(int a, int b){
			return query(a, b, 0, 0, n);
		}
	}
	
	public static void main(String[] args) throws IOException {	
		try(final Scanner sc = new Scanner(System.in)){
			final int H = sc.nextInt();
			final int W = sc.nextInt();
			final int M = sc.nextInt();
			
			ArrayList<HashSet<Integer>> bombs = new ArrayList<HashSet<Integer>>();
			for(int i = 0; i < H; i++) { bombs.add(new HashSet<Integer>()); }
			
			long[] rows = new long[H];
			long[] cols = new long[W];
			
			for(int i = 0; i < M; i++) {
				final int h = sc.nextInt() - 1;
				final int w = sc.nextInt() - 1;
				
				rows[h]++;
				cols[w]++;
				bombs.get(h).add(w);
			}
			
			SegTree seg = new SegTree(W);
			for(int i = 0; i < W; i++) {
				seg.add(i, cols[i]);
			}
			
			long answer = 0;
			for(int row = 0; row < H; row++) {
				for(int col : bombs.get(row)) {
					seg.add(col, -1);
				}
				
				answer = Math.max(answer, rows[row] + seg.query(0, W));
				
				for(int col : bombs.get(row)) {
					seg.add(col, +1);
				}
			}
			
			System.out.println(answer);
		}
	}

	public static class Scanner implements Closeable {
		private BufferedReader br;
		private StringTokenizer tok;

		public Scanner(InputStream is) throws IOException {
			br = new BufferedReader(new InputStreamReader(is));
		}

		private void getLine() throws IOException {
			while(!hasNext()){
				tok = new StringTokenizer(br.readLine());
			}
		}

		private boolean hasNext() {
			return tok != null && tok.hasMoreTokens();
		}

		public String next() throws IOException {
			getLine();
			return tok.nextToken();
		}

		public int nextInt() throws IOException {
			return Integer.parseInt(next());
		}

		public long nextLong() throws IOException {
			return Long.parseLong(next());
		}
		

		public double nextDouble() throws IOException {
			return Double.parseDouble(next());
		}

		public int[] nextIntArray(int n) throws IOException {
			final int[] ret = new int[n];
			for(int i = 0; i < n; i++){
				ret[i] = this.nextInt();
			}
			return ret;
		}

		public long[] nextLongArray(int n) throws IOException {
			final long[] ret = new long[n];
			for(int i = 0; i < n; i++){
				ret[i] = this.nextLong();
			}
			return ret;
		}

		public void close() throws IOException {
			br.close();
		}
	}
}


Measured memory_bytes: 150260