#ifdef LOCAL111
	#define _GLIBCXX_DEBUG
#else
	#define NDEBUG
#endif
#define _USE_MATH_DEFINES
#ifndef _GLIBCXX_NO_ASSERT
#include <cassert>
#endif
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>

#if __cplusplus >= 201103L
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>
#endif

// C++
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>

#if __cplusplus >= 201103L
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <type_traits>
#include <typeindex>
#include <unordered_map>
#include <unordered_set>
#endif
const int INF = 1e9;
using namespace std;
template<typename T, typename U> ostream& operator<< (ostream& os, const pair<T,U>& p) { os << '(' << p.first << ' ' << p.second << ')'; return os; }

#define endl '\n'
#define ALL(a)  (a).begin(),(a).end()
#define SZ(a) int((a).size())
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n)  FOR(i,0,n)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)
#ifdef LOCAL111
	#define DEBUG(x) cout<<#x<<": "<<(x)<<endl
	template<typename T> void dpite(T a, T b){ for(T ite = a; ite != b; ite++) cout << (ite == a ? "" : " ") << *ite; cout << endl;}
#else
	#define DEBUG(x) true
	template<typename T> void dpite(T a, T b){ return; }
#endif
#define F first
#define S second
#define SNP string::npos
#define WRC(hoge) cout << "Case #" << (hoge)+1 << ": "
template<typename T> void pite(T a, T b){ for(T ite = a; ite != b; ite++) cout << (ite == a ? "" : " ") << *ite; cout << endl;}
template<typename T> bool chmax(T& a, T b){if(a < b){a = b; return true;} return false;}
template<typename T> bool chmin(T& a, T b){if(a > b){a = b; return true;} return false;}

typedef long long int LL;
typedef unsigned long long ULL;
typedef pair<int,int> P;

void ios_init(){
	//cout.setf(ios::fixed);
	//cout.precision(12);
#ifdef LOCAL111
	return;
#endif
	ios::sync_with_stdio(false); cin.tie(0);
}

typedef long long cost_t;

class Edge {
public:
  int to = -1, from = -1, rev = -1;
  cost_t cost = -1, cap = -1;

  Edge() {}

  Edge(int x, cost_t y) {
    to = x;
    cost = y;
  }

  Edge(int x, int y, cost_t z) {
    from = x;
    to = y;
    cost = z;
  }

  Edge(int x, int y, int r, cost_t z) {
    from = x;
    to = y;
    cost = z;
    rev = r;
  }

  Edge(int x, int y, int r, cost_t co, cost_t ca) {
    from = x;
    to = y;
    cost = co;
    cap = ca;
    rev = r;
  }

  bool operator<(const Edge &x) const {
    if (cost != x.cost)
      return cost < x.cost;
    return to < x.to;
  }

  bool operator>(const Edge &x) const {
    if (cost != x.cost)
      return cost > x.cost;
    return to > x.to;
  }
};

class Graph {
private:
  typedef vector<Edge> Edges;
  // const long long int INF = (long long)1e18;
  vector<Edges> v;
  int n;

public:
  Graph(int x) {
    n = x;
    v = vector<Edges>(x);
  }

  Graph() {}

  Edges &operator[](int x) { return v[x]; }

  const Edges &operator[](int x) const { return v[x]; }

  int size() const { return n; }

  void add_edge(int from, const Edge &e) { v[from].push_back(e); }

  void add_edge(int from, int to, cost_t cost = -1, cost_t cap = -1,
                int rev = -1) {
    add_edge(from, Edge(from, to, rev, cost, cap));
  }

  void add_fedge(int from, int to, cost_t cap = -1) {
    add_edge(from, to, -1, cap, -1);
  }

  void add_uedge(int from, int to, cost_t cost = -1) {
    add_edge(from, to, cost);
    add_edge(to, from, cost);
  }
};

cost_t dMaxFlow(const Graph &g_, int s, int t) {
  Graph g = g_;
  assert(s != t);
  int n = g.size();
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < int(g_[i].size()); j++) {
      auto &&e = g[i][j];
      e.rev = g[e.to].size();
      g.add_edge(e.to, i, -1, 0, j);
    }
  }

  cost_t flow = 0;
  while (true) {
    vector<int> level(n, -1);
    level[s] = 0;
    queue<int> que;
    que.push(s);
    while (!que.empty()) {
      int v = que.front();
      que.pop();
      for (auto &&e : g[v]) {
        if (e.cap > 0 and level[e.to] < 0) {
          level[e.to] = level[v] + 1;
          que.push(e.to);
        }
      }
    }

    if (level[t] < 0)
      return flow;

    vector<int> iter(n, 0);
    function<cost_t(int, int)> dfs = [&](int v, cost_t f) -> cost_t {
      if (v == t)
        return f;
      for (int &i = iter[v]; i < (int)g[v].size(); ++i) {
        auto &e = g[v][i];
        if (e.cap <= 0 or level[v] >= level[e.to])
          continue;
        int d = dfs(e.to, min(f, e.cap));
        if (d > 0) {
          e.cap -= d;
          g[e.to][e.rev].cap += d;
          return d;
        }
      }
      return 0;
    };

    cost_t f;
    while ((f = dfs(s, INF)) > 0) {
      flow += f;
    }
  }
}

int main()
{
	ios_init();
    int n;
    while(cin >> n) {
        vector<P> r(n);
        vector<P> b(n);
        REP(i, n) cin >> r[i].F >> r[i].S;
        REP(i, n) cin >> b[i].F >> b[i].S;
        Graph g(2*n+2);
        int s = 2*n;
        int t = 2*n+1;
        REP(i, n) REP(j, n) {
            if(r[i].F < b[j].F and r[i].S < b[j].S) {
                g.add_fedge(i, n+j, 1);
            }
        }
        REP(i, n) g.add_fedge(s, i, 1);
        REP(i, n) g.add_fedge(n+i, t, 1);
        cout << dMaxFlow(g, s, t) << endl;
    }
	return 0;
}


Measured memory_bytes: 768