import core.bitop;
import std.algorithm;
import std.ascii;
import std.bigint;
import std.conv;
import std.functional;
import std.math;
import std.numeric;
import std.range;
import std.stdio;
import std.string;
import std.random;
import std.typecons;
import std.container;

alias sread = () => readln.chomp();
ulong MOD = 1_000_000_007;
ulong INF = 1_000_000_000_000;
alias Grid = Tuple!(long, "x", long, "y");

T lread(T = long)()
{
    return readln.chomp.to!T();
}

T[] aryread(T = long)()
{
    return readln.split.to!(T[])();
}

void scan(TList...)(ref TList Args)
{
    auto line = readln.split();
    foreach (i, T; TList)
    {
        T val = line[i].to!(T);
        Args[i] = val;
    }
}

void main()
{
    auto n = lread();
    auto a = new Grid[](n);
    auto c = new Grid[](n);
    auto pair = new long[](n);
    foreach (i; iota(n))
    {
        long x, y;
        scan(x, y);
        a[i] = Grid(x, y);
    }
    foreach (i; iota(n))
    {
        long x, y;
        scan(x, y);
        c[i] = Grid(x, y);
    }
    a.sort!"a.y > b.y"();
    c.sort();
    foreach (e; c)
    {
        long tmp;
        while (1)
        {
            if (tmp >= n)
                break;

            if (!pair[tmp] && a[tmp].x < e.x && a[tmp].y < e.y)
            {
                pair[tmp]++;
                break;
            }
            tmp++;
        }
    }
    pair.sum.writeln();
}
