import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.net.ConnectException;
import java.rmi.dgc.Lease;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Deque;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Objects;
import java.util.Set;
import java.util.Stack;
import java.util.TreeMap;
import java.util.TreeSet;

import static java.util.Comparator.*;

public class Main {
	public static void main(String[] args) {
		Main main = new Main();
		main.solve();
		main.out.close();
	}
	// ======================================================================
	int[] HC, WC;
	Set<PPKEY> set = new HashSet();
	public void solve() {
		int H = ni();
		int W = ni();
		HC = new int[H];
		WC = new int[W];
		int M = ni();
		int h, w;
		for (int i = 0; i < M; i++) {
			h = ni() - 1;
			w = ni() - 1;
			HC[h]++;
			WC[w]++;
			set.add(new PPKEY(h,w));
		}
		List<Integer> hList = new ArrayList();
		int hMax = 0;
		for (int i = 0; i < H; i++) {
			if(hMax < HC[i]) {
				hMax = HC[i];
				hList.clear();
				hList.add(i);
			} else if(hMax == HC[i]){
				hList.add(i);
			}
		}
		List<Integer> wList = new ArrayList();
		int wMax = 0;
		for (int i = 0; i < W; i++) { 
			if(wMax < WC[i]) {
				wMax = WC[i];
				wList.clear();
				wList.add(i);
			} else if(wMax == WC[i]){
				wList.add(i);
			}
		}
		int dec = 1;
		boolean f;
		LOOP:
		for(int hh : hList) {
			for(int ww : wList) {
				if(!set.contains(new PPKEY(hh,ww))){
					dec = 0;
					break LOOP;
				}
//				f = false;
//				for(PPKEY pp : set) {
////					out.println("[" + pp.key + "][" + pp.val + "]");
//					if(pp.key == hh && pp.val == ww) {
//						f = true;
//						break;
//					}
//				}
//				if(!f) {
//					dec = 0;
//					break LOOP;
//				}
			}
		}
		out.println(hMax + wMax - dec);
	}
    // HashMap のキーに使う　→　Set に入れるのもこれ（PPでは値での比較が行われない）
    static final class PPKEY{
    	private final int key, val;
    	public PPKEY(int key, int val) {
    		this.key = key;
    		this.val = val;
    	}
		public int getKey() {
			return key;
		}
		public int getVal() {
			return val;
		}
	    @Override
	    public boolean equals(Object obj) {
	        if (obj instanceof PPKEY) {
	        	PPKEY dest = (PPKEY) obj;
	            return this.key == dest.key && this.val == dest.val;
	        } else {
	            return false;
	        }
	    }
	    @Override
	    public int hashCode() {
	        return Objects.hash(key, val);
	    }
    }
//	// HashMap のキーに使う　→　Set に入れるのもこれ（PPでは値での比較が行われない）
//	public class PPKEY implements Comparable<PPKEY>{
//		int key, val;
//		public PPKEY(int key, int val) {
//			this.key = key;
//			this.val = val;
//		}
//		public int getKey() {			return key;	}
//		public void setKey(int key) {	this.key = key; }
//		public int getVal() {			return val;	}
//		public void setVal(int val) {	this.val = val;	}
//		@Override
//		public int compareTo(PPKEY target) {	// key , val の順で比較する
////			out.println("[" + key + "][" + val + "] と　"
////							+ "[" + target.key + "][" + target.val + "]　を比較する");
//			if(key != target.key) {
//				return Integer.compare(key,  target.key);
//			}
//			return Integer.compare(val, target.val);
//		}
//	}

	// ------------------------------------------
	// ライブラリ
	// ------------------------------------------
	// Print
	private PrintWriter out = new PrintWriter(System.out);
	
	// Scanner
	private FastScanner scan = new FastScanner();
	int ni(){ return scan.nextInt();}
	int[] ni(int n){int[] a = new int[n]; for(int i = 0; i < n; i++){a[i] = ni();} return a;}
	int[][] ni(int y, int x){int[][] a = new int[y][x];
	for(int i = 0; i < y; i++){for(int j = 0; j < x; j++){a[i][j] = ni();}} return a;}
	long nl(){return scan.nextLong();}
	long[] nl(int n){long[] a = new long[n]; for(int i = 0; i < n; i++){a[i] = nl();} return a;}
	long[][] nl(int y, int x){long[][] a = new long[y][x];
	for(int i = 0; i < y; i++){for(int j = 0; j < x; j++){a[i][j] = nl();}} return a;}
	String ns(){return scan.next();}
	String[] ns(int n){String[] a = new String[n]; for(int i = 0; i < n; i++){a[i] = ns();} return a;}
	String[][] ns(int y, int x){String[][] a = new String[y][x];
	for(int i = 0; i < y; i++){for(int j = 0; j < x; j++){a[i][j] = ns();}} return a;}
}
class FastScanner {
	private final InputStream in = System.in;
	private final byte[] buffer = new byte[1024];
	private int ptr = 0;
	private int buflen = 0;
	private boolean hasNextByte() {
		if (ptr < buflen) {
			return true;
		}else{
			ptr = 0;
			try {
				buflen = in.read(buffer);
			} catch (IOException e) {
				e.printStackTrace();
			}
			if (buflen <= 0) {
				return false;
			}
		}
		return true;
	}
	private int readByte() { if (hasNextByte()) return buffer[ptr++]; else return -1;}
	private static boolean isPrintableChar(int c) { return 33 <= c && c <= 126;}
	public boolean hasNext() { while(hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++; return hasNextByte();}
	public String next() {
		if (!hasNext()) throw new NoSuchElementException();
		StringBuilder sb = new StringBuilder();
		int b = readByte();
		while(isPrintableChar(b)) {
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	public long nextLong() {
		if (!hasNext()) throw new NoSuchElementException();
		long n = 0;
		boolean minus = false;
		int b = readByte();
		if (b == '-') {
			minus = true;
			b = readByte();
		}
		if (b < '0' || '9' < b) {
			throw new NumberFormatException();
		}
		while(true){
			if ('0' <= b && b <= '9') {
				n *= 10;
				n += b - '0';
			}else if(b == -1 || !isPrintableChar(b)){
				return minus ? -n : n;
			}else{
				throw new NumberFormatException();
			}
			b = readByte();
		}
	}
	public int nextInt() {
		long nl = nextLong();
		if (nl < Integer.MIN_VALUE || nl > Integer.MAX_VALUE) throw new NumberFormatException();
		return (int) nl;
	}
	public double nextDouble() { return Double.parseDouble(next());}
}


Measured memory_bytes: 87384