#include <algorithm>

#include <vector>

namespace atcoder {

namespace internal {

template <class T> struct simple_queue {
    std::vector<T> payload;
    int pos = 0;
    void reserve(int n) { payload.reserve(n); }
    int size() const { return int(payload.size()) - pos; }
    bool empty() const { return pos == int(payload.size()); }
    void push(const T& t) { payload.push_back(t); }
    T& front() { return payload[pos]; }
    void clear() {
        payload.clear();
        pos = 0;
    }
    void pop() { pos++; }
};

}  // namespace internal

}  // namespace atcoder

#include <cassert>
#include <limits>
#include <queue>
#include <vector>

namespace atcoder {

template <class Cap> struct mf_graph {
  public:
    mf_graph() : _n(0) {}
    mf_graph(int n) : _n(n), g(n) {}

    int add_edge(int from, int to, Cap cap) {
        assert(0 <= from && from < _n);
        assert(0 <= to && to < _n);
        assert(0 <= cap);
        int m = int(pos.size());
        pos.push_back({from, int(g[from].size())});
        g[from].push_back(_edge{to, int(g[to].size()), cap});
        g[to].push_back(_edge{from, int(g[from].size()) - 1, 0});
        return m;
    }

    struct edge {
        int from, to;
        Cap cap, flow;
    };

    edge get_edge(int i) {
        int m = int(pos.size());
        assert(0 <= i && i < m);
        auto _e = g[pos[i].first][pos[i].second];
        auto _re = g[_e.to][_e.rev];
        return edge{pos[i].first, _e.to, _e.cap + _re.cap, _re.cap};
    }
    std::vector<edge> edges() {
        int m = int(pos.size());
        std::vector<edge> result;
        for (int i = 0; i < m; i++) {
            result.push_back(get_edge(i));
        }
        return result;
    }
    void change_edge(int i, Cap new_cap, Cap new_flow) {
        int m = int(pos.size());
        assert(0 <= i && i < m);
        assert(0 <= new_flow && new_flow <= new_cap);
        auto& _e = g[pos[i].first][pos[i].second];
        auto& _re = g[_e.to][_e.rev];
        _e.cap = new_cap - new_flow;
        _re.cap = new_flow;
    }

    Cap flow(int s, int t) {
        return flow(s, t, std::numeric_limits<Cap>::max());
    }
    Cap flow(int s, int t, Cap flow_limit) {
        assert(0 <= s && s < _n);
        assert(0 <= t && t < _n);

        std::vector<int> level(_n), iter(_n);
        internal::simple_queue<int> que;

        auto bfs = [&]() {
            std::fill(level.begin(), level.end(), -1);
            level[s] = 0;
            que.clear();
            que.push(s);
            while (!que.empty()) {
                int v = que.front();
                que.pop();
                for (auto e : g[v]) {
                    if (e.cap == 0 || level[e.to] >= 0) continue;
                    level[e.to] = level[v] + 1;
                    if (e.to == t) return;
                    que.push(e.to);
                }
            }
        };
        auto dfs = [&](auto self, int v, Cap up) {
            if (v == s) return up;
            Cap res = 0;
            int level_v = level[v];
            for (int& i = iter[v]; i < int(g[v].size()); i++) {
                _edge& e = g[v][i];
                if (level_v <= level[e.to] || g[e.to][e.rev].cap == 0) continue;
                Cap d =
                    self(self, e.to, std::min(up - res, g[e.to][e.rev].cap));
                if (d <= 0) continue;
                g[v][i].cap += d;
                g[e.to][e.rev].cap -= d;
                res += d;
                if (res == up) break;
            }
            return res;
        };

        Cap flow = 0;
        while (flow < flow_limit) {
            bfs();
            if (level[t] == -1) break;
            std::fill(iter.begin(), iter.end(), 0);
            while (flow < flow_limit) {
                Cap f = dfs(dfs, t, flow_limit - flow);
                if (!f) break;
                flow += f;
            }
        }
        return flow;
    }

    std::vector<bool> min_cut(int s) {
        std::vector<bool> visited(_n);
        internal::simple_queue<int> que;
        que.push(s);
        while (!que.empty()) {
            int p = que.front();
            que.pop();
            visited[p] = true;
            for (auto e : g[p]) {
                if (e.cap && !visited[e.to]) {
                    visited[e.to] = true;
                    que.push(e.to);
                }
            }
        }
        return visited;
    }

  private:
    int _n;
    struct _edge {
        int to, rev;
        Cap cap;
    };
    std::vector<std::pair<int, int>> pos;
    std::vector<std::vector<_edge>> g;
};

}  // namespace atcoder

#include <bits/stdc++.h>
#define rep(a,n) for (ll a = 0; a < (n); ++a)
using namespace std;
using namespace atcoder;
using ll = long long;
typedef pair<ll,ll> P;
typedef pair<ll,P> PP;
typedef vector<vector<int> > Graph;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const ll INF = numeric_limits<ll>::max();


#define debug(v) cout<<#v<<": ",prt(v);
template <typename A,typename B>
inline void prt(pair<A,B> p){cout<<"("<<p.first<<", "<<p.second<<")\n";}
template <typename A,typename B,typename C>
inline void prt(tuple<A,B,C> p){cout<<"("<<get<0>(p)<<", "<<get<1>(p)<<", "<<get<2>(p)<<")\n";}
inline void prt(bool p){if(p)cout<<"True"<<'\n';else cout<<"False"<<'\n';}
template <typename T> 
inline void prt(vector<T> v){cout<<'{';for(ll i=0;i<v.size();i++){cout<<v[i];if(i<v.size()-1)cout<<", ";}cout<<'}'<<'\n';}
template <typename T> 
inline void prt(deque<T> v){cout<<'{';for(ll i=0;i<v.size();i++){cout<<v[i];if(i<v.size()-1)cout<<", ";}cout<<'}'<<'\n';}
template <typename A,typename B>
inline void prt(map<A,B> v){cout<<'{';ll c=0;for(auto &p: v){cout<<p.first<<":"<<p.second;c++;if(c!=v.size())cout<<", ";}cout<<'}'<<'\n';}
template <typename A,typename B>
inline void prt(unordered_map<A,B> v){cout<<'{';ll c=0;for(auto &p: v){cout<<p.first<<":"<<p.second;c++;if(c!=v.size())cout<<", ";}cout<<'}'<<'\n';}
template <typename T> 
inline void prt(set<T> v){cout<<'{';for(auto i=v.begin();i!=v.end();i++){cout<<*i;if(i!=--v.end())cout<<", ";}cout<<'}'<<'\n';}
template <typename T> 
inline void prt(multiset<T> v){cout<<'{';for(auto i=v.begin();i!=v.end();i++){cout<<*i;if(i!=--v.end())cout<<", ";}cout<<'}'<<'\n';}

int main(){
    ll n;
    cin >> n;
    vector<ll>a(n),b(n),c(n),d(n);
    rep(i,n)cin>>a[i]>>b[i];
    rep(i,n)cin>>c[i]>>d[i];
    mf_graph<ll>graph(2*n+2);
    rep(i,n){
        graph.add_edge(0,i+1,1);
        graph.add_edge(n+1+i,2*n+1,1);
    }
    rep(i,n){
        rep(j,n){
            if(a[i]<c[j]&&b[i]<d[j])graph.add_edge(i+1,n+1+j,1);
        }
    }
    cout << graph.flow(0,2*n+1) << endl;


    return 0;
}


Measured memory_bytes: 3840