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



class Solve
{
    public Solve() { }
    public static int Main()
    {
        new Solve().calc();
        return 0;
    }


    Scanner cin;

    void calc()
    {
        cin = new Scanner();
        int N = cin.nextInt();
        var points = new Point[2*N];
        for(int i=0; i<2*N; i++)
        {
            int color = i < N ? 0 : 1;
            points[i] = new Point(color, cin.nextInt(), cin.nextInt());
        }
        var sorted = points.OrderBy(a => a.X);
        var set = new List<Point>();
        var matchedCount = 0;
        foreach (var point in sorted)
        {
            if(point.Color == 0)//red
            {
                set.Add(point);
            }
            else//blue
            {
                if(set.Count() > 0)
                {
                    var highestIndex = 0;
                    var highestRedY = int.MinValue;
                    var indexCount = 0;
                    var isMatched = false;
                    foreach(var s in set)
                    {
                        if(s.Y < point.Y && s.Y > highestRedY)
                        {
                            highestRedY = s.Y;
                            highestIndex = indexCount;
                            isMatched = true;
                        }
                        indexCount++;
                    }
                    if(isMatched)
                    {
                        set[highestIndex].Y = int.MaxValue;
                        matchedCount++;
                    }
                }
            }
        }
        Console.WriteLine(matchedCount.ToString());
        
    }
}
public class Point
{
    public int Color;
    public int X;
    public int Y;
    public Point(int color, int x, int y)
    {
        Color = color;
        X = x;
        Y = y;
    }
}

class Scanner
{
    string[] s;
    int i;

    char[] cs = new char[] { ' ' };

    public Scanner()
    {
        s = new string[0];
        i = 0;
    }

    public string next()
    {
        if (i < s.Length) return s[i++];
        string st = Console.ReadLine();
        while (st == "") st = Console.ReadLine();
        s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
        if (s.Length == 0) return next();
        i = 0;
        return s[i++];
    }

    public int nextInt()
    {
        return int.Parse(next());
    }
    public int[] ArrayInt(int N, int add = 0)
    {
        int[] Array = new int[N];
        for (int i = 0; i < N; i++)
        {
            Array[i] = nextInt() + add;
        }
        return Array;
    }

    public long nextLong()
    {
        return long.Parse(next());
    }

    public long[] ArrayLong(int N, long add = 0)
    {
        long[] Array = new long[N];
        for (int i = 0; i < N; i++)
        {
            Array[i] = nextLong() + add;
        }
        return Array;
    }

    public double nextDouble()
    {
        return double.Parse(next());
    }


    public double[] ArrayDouble(int N, double add = 0)
    {
        double[] Array = new double[N];
        for (int i = 0; i < N; i++)
        {
            Array[i] = nextDouble() + add;
        }
        return Array;
    }
}

Measured memory_bytes: 13396