import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;
public class Main
{
    private final int NIL = 0;
    private final int INF = Integer.MAX_VALUE;
    private ArrayList<Integer>[] Adj;
    private int[] Pair;
    private int[] Dist;
    private int cx, cy;
    public boolean BFS()
    {
        Queue<Integer> queue = new LinkedList<Integer>();
        for (int v = 1; v <= cx; ++v)
            if (Pair[v] == NIL)
            {
                Dist[v] = 0;
                queue.add(v);
            }
            else
                Dist[v] = INF;

        Dist[NIL] = INF;

        while (!queue.isEmpty())
        {
            int v = queue.poll();
            if (Dist[v] < Dist[NIL])
                for (int u : Adj[v])
                    if (Dist[Pair[u]] == INF)
                    {
                        Dist[Pair[u]] = Dist[v] + 1;
                        queue.add(Pair[u]);
                    }
        }
        return Dist[NIL] != INF;
    }
    public boolean DFS(int v)
    {
        if (v != NIL)
        {
            for (int u : Adj[v])
                if (Dist[Pair[u]] == Dist[v] + 1)
                    if (DFS(Pair[u]))
                    {
                        Pair[u] = v;
                        Pair[v] = u;
                        return true;
                    }

            Dist[v] = INF;
            return false;
        }
        return true;
    }
    public int HopcroftKarp()
    {
        Pair = new int[cx + cy + 1];
        Dist = new int[cx + cy + 1];
        int matching = 0;
        while (BFS())
            for (int v = 1; v <= cx; ++v)
                if (Pair[v] == NIL)
                    if (DFS(v))
                        matching = matching + 1;
        return matching;
    }
    /** Function to make graph with vertices x , y **/
    public void makeGraph(int[] x, int[] y, int E)
    {
        Adj = new ArrayList[cx + cy + 1];
        for (int i = 0; i < Adj.length; ++i)
            Adj[i] = new ArrayList<Integer>();
        /** adding edges **/
        for (int i = 0; i < E; ++i)
            addEdge(x[i] + 1, y[i] + 1);
    }
    /** Function to add a edge **/
    public void addEdge(int u, int v)
    {
        Adj[u].add(cx + v);
        Adj[cx + v].add(u);
    }
    /** Main Method **/
    public static void main (String[] args)
    {
        Scanner scan = null;
        try {
            scan = new Scanner(new File("cuplaj.in"));
        } catch (IOException e) {
            System.exit(-1);
        }
        scan.nextInt(); scan.nextInt();
        Main hc = new Main();

        int E = scan.nextInt();
        int[] x = new int[E];
        int[] y = new int[E];
        hc.cx = 0;
        hc.cy = 0;

        for (int i = 0; i < E; i++)
        {
            x[i] = scan.nextInt();
            y[i] = scan.nextInt();
            hc.cx = Math.max(hc.cx, x[i]);
            hc.cy = Math.max(hc.cy, y[i]);
        }
        hc.cx += 1;
        hc.cy += 1;

        hc.makeGraph(x, y, E);

        PrintWriter printWriter = null;
        try {
            printWriter = new PrintWriter(new FileWriter("cuplaj.out"));
            printWriter.print(hc.HopcroftKarp());
        } catch (IOException e) {
            System.exit(-1);
        } finally {
            if (printWriter != null) {
                printWriter.close();
            }
        }
    }
}