import java.io.IOException;
import java.util.NoSuchElementException;

import java.io.InputStream;

import java.io.PrintWriter;

import java.util.Arrays;
import java.util.Comparator;

class Point {
    int x;
    int y;
    Point(int x, int y) {
        this.x = x;
        this.y = y;
    }
}

@SuppressWarnings("unchecked")
public class Main {
    public static void main(String[] args) throws IOException {
        FastScanner fs = new FastScanner();
        PrintWriter out = new PrintWriter(System.out);

        final int N = fs.nextInt();

        Point[] R = new Point[N];
        Point[] B = new Point[N];
        int[] A = new int[N];

        for (int i = 0; i < N; i++)
            R[i] = new Point(fs.nextInt(), fs.nextInt());

        for (int i = 0; i < N; i++)
            B[i] = new Point(fs.nextInt(), fs.nextInt());

        // x 降順
        Arrays.sort(R, new Comparator<Point>() {
            public int compare(Point p1, Point p2) {
                return p2.x - p1.x;
            }
        });

        // y 昇順
        Arrays.sort(B, new Comparator<Point>() {
            public int compare(Point p1, Point p2) {
                return p1.y - p2.y;
            }
        });

        // ペアになった青
        boolean[] done = new boolean[N];

        for (int i = 0; i < N; i++)
            for (int j = 0; j < N; j++)
                if (!done[j] && R[i].x < B[j].x && R[i].y < B[j].y) {
                    done[j] = true;
                    break;
                }

        int cnt = 0;

        for (int i = 0; i < N; i++) if (done[i]) cnt++;

        out.println(cnt);

        out.flush();
    }
}

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: 22484