#include <bits/stdc++.h>
using namespace std;
#ifndef ONLINE_JUDGE
	#include <boost/multiprecision/cpp_int.hpp>
	#include <boost/multiprecision/cpp_dec_float.hpp>
	using bll = boost::multiprecision::cpp_int;
	using bdouble = boost::multiprecision::cpp_dec_float_100;
#endif
#ifdef LOCAL_DEV
	void debug_impl() { std::cerr << std::endl; }
	template<typename Head, typename... Tail> void debug_impl(Head head, Tail... tail) { std::cerr << " " << head << (sizeof...(tail) ? "," : ""); debug_impl(tail...); }
	#define debug(...) std::cerr << std::boolalpha << "(" << #__VA_ARGS__ << ") ="; debug_impl(__VA_ARGS__); std::cerr << std::noboolalpha;
#else
	#define debug(...)
#endif
#ifdef LOCAL_TEST
	#define BOOST_STACKTRACE_USE_ADDR2LINE
	#define BOOST_STACKTRACE_ADDR2LINE_LOCATION /usr/local/opt/binutils/bin/addr2line
	#define _GNU_SOURCE
	#include <boost/stacktrace.hpp>
	template<typename T> class dvector : public std::vector<T> {
	public:
		dvector() : std::vector<T>() {}
		explicit dvector(size_t n, const T& value = T()) : std::vector<T>(n, value) {}
		dvector(const std::vector<T>& v) : std::vector<T>(v) {}
		dvector(const std::initializer_list<T> il) : std::vector<T>(il) {}
		dvector(const typename std::vector<T>::iterator first, const typename std::vector<T>::iterator last) : std::vector<T>(first, last) {}
		dvector(const std::string::iterator first, const std::string::iterator last) : std::vector<T>(first, last) {}
		T& operator[](size_t n) {
			try { return this->at(n); } catch (const std::exception& e) {
				std::cerr << boost::stacktrace::stacktrace() << std::endl; return this->at(n);
			}
		}
		const T& operator[](size_t n) const {
			try { return this->at(n); } catch (const std::exception& e) {
				std::cerr << boost::stacktrace::stacktrace() << std::endl; return this->at(n);
			}
		}
	};
	class dbool {
	private:
		bool boolvalue;
	public:
		dbool() : boolvalue(false) {}
		dbool(bool b) : boolvalue(b) {}
		dbool(const dbool &b) : boolvalue(b.boolvalue) {}
		operator bool&() { return boolvalue; }
		operator const bool&() const { return boolvalue; }
	};
	template<typename T> std::ostream& operator<<(std::ostream& s, const dvector<T>& v) {
		for (int i = 0, len = v.size(); i < len; ++i){ s << v[i]; if (i < len - 1) s << "\t"; } return s; }
	template<typename T> std::ostream& operator<<(std::ostream& s, const dvector< dvector<T> >& vv) {
		for (int i = 0, len = vv.size(); i < len; ++i){ s << vv[i] << std::endl; } return s; }
	template<typename T> std::ostream& operator<<(std::ostream& s, const std::set<T>& se) {
		s << "{ "; for (auto itr = se.begin(); itr != se.end(); ++itr){ s << (*itr) << "\t"; } s << "}" << std::endl; return s; }
	template<typename T> std::ostream& operator<<(std::ostream& s, const std::multiset<T>& se) {
		s << "{ "; for (auto itr = se.begin(); itr != se.end(); ++itr){ s << (*itr) << "\t"; } s << "}" << std::endl; return s; }
	template<typename T1, typename T2> std::ostream& operator<<(std::ostream& s, const std::map<T1, T2>& m) {
		s << "{" << std::endl; for (auto itr = m.begin(); itr != m.end(); ++itr){ s << "\t" << (*itr).first << " : " << (*itr).second << std::endl; } s << "}" << std::endl; return s; }
	template<typename T1, typename T2> std::ostream& operator<<(std::ostream& s, const std::pair<T1, T2>& p) { 
		return s << "(" << p.first << ", " << p.second << ")"; }
	#define vector dvector
	#define bool dbool
#endif
//#define int long long
using ll = long long;
//constexpr int INF = 1e9;//INT_MAX=(1<<31)-1=2147483647
constexpr ll INF = (ll)1e18;//(1LL<<63)-1=9223372036854775807
constexpr ll MOD = (ll)1e9 + 7;
constexpr double EPS = 1e-9;
constexpr int dx[4]={1,0,-1,0};
constexpr int dy[4]={0,1,0,-1};
#define p(var) std::cout<<var<<std::endl
#define rep(i, n)   for(ll i=0, i##_length=(n); i< i##_length; ++i)
#define repeq(i, n) for(ll i=1, i##_length=(n); i<=i##_length; ++i)
#define all(v) (v).begin(), (v).end()
#define uniq(v) (v).erase(unique((v).begin(), (v).end()), (v).end());
template<typename T> inline void pv(vector<T> &v) { for(ll i=0, N=v.size(); i<N; i++) std::cout << v[i] << " \n"[i==N-1]; }
template<typename T> inline T gcd(T a, T b) { return b ? gcd(b,a%b) : a; }
template<typename T> inline T lcm(T a, T b) { return a / gcd(a,  b) * b; }
template<typename T1, typename T2> inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }
template<typename T1, typename T2> inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }

/*-----8<-----template-----8<-----*/

/*
計算量：O(E*maxflow)
FordFulkerson(V):= 頂点数 V で初期化する。
add_edge(from, to, cap):= 頂点 from から to に容量 cap の辺を張る。
max_flow(s, t):= 頂点 s から t に最大流を流し、その流量を返す。
*/
template< typename flow_t >
class FordFulkerson {
public:
	class edge {
		public:
		ll to;
		flow_t cap;
		ll rev;
		bool isrev;
		ll idx;
	};

	vector< vector< edge > > graph;
	vector< ll > used;
	const flow_t INF;
	ll timestamp;

	FordFulkerson(ll n) : INF(numeric_limits< flow_t >::max()), timestamp(0) {
		graph.resize(n);
		used.assign(n, -1);
	}

	void add_edge(ll from, ll to, flow_t cap, ll idx = -1) {
		graph[from].emplace_back((edge) {to, cap, (ll) graph[to].size(), false, idx});
		graph[to].emplace_back((edge) {from, 0, (ll) graph[from].size() - 1, true, idx});
	}

	flow_t dfs(ll idx, const ll t, flow_t flow) {
		if(idx == t) return flow;
		used[idx] = timestamp;
		for(auto &e : graph[idx]) {
			if(e.cap > 0 && used[e.to] != timestamp) {
				flow_t d = dfs(e.to, t, min(flow, e.cap));
				if(d > 0) {
					e.cap -= d;
					graph[e.to][e.rev].cap += d;
					return d;
				}
			}
		}
		return 0;
	}

	flow_t max_flow(ll s, ll t) {
		flow_t flow = 0;
		for(flow_t f; (f = dfs(s, t, INF)) > 0; timestamp++) {
			flow += f;
		}
		return flow;
	}

	void output() {
		for(ll i = 0; i < graph.size(); i++) {
			for(auto &e : graph[i]) {
				if(e.isrev) continue;
				auto &rev_e = graph[e.to][e.rev];
				cout << i << "->" << e.to << " (flow: " << rev_e.cap << "/" << e.cap + rev_e.cap << ")" << endl;
			}
		}
	}
};

/*-----8<-----library-----8<-----*/

signed main() {
	//ABC091C
	//https://atcoder.jp/contests/abc091/tasks/arc092_a
	ll N;
	cin>>N;
	vector<pair<ll,ll>> a(N),c(N);
	rep(i,N){
		cin>>a[i].first>>a[i].second;
	}
	rep(i,N){
		cin>>c[i].first>>c[i].second;
	}

	FordFulkerson<ll> g(2*N+2);
	repeq(i,N){
		g.add_edge(0, i, 1);
		g.add_edge(N+i, 2*N+1, 1);
	}

	rep(i,N){
		rep(j,N){
			if(a[i].first<c[j].first && a[i].second<c[j].second){
				g.add_edge(i+1, N+j+1, 1);
			}
		}
	}

	ll ans=g.max_flow(0, 2*N+1);
	//g.output();
	p(ans);
	return 0;
}


Measured memory_bytes: 640