#include <bits/stdc++.h>
using namespace std;

//#define int long long
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define rep(i,n) for(int i=0;i<n;++i)
#define rep1(i,n) for(int i=1;i<n;++i)
#define exrep(i, a, b) for(ll i = a; i < b; i++)
#define out(x) cout << x << endl
#define EPS (1e-7)
#define gearup ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
typedef long double ld;
typedef long long int ll;
typedef unsigned long long int ull;
typedef vector<int> vi;
typedef vector<char> vc;
typedef vector<bool> vb;
typedef vector<double> vd;
typedef vector<string> vs;
typedef vector<pair<int,int> > vpii;
typedef vector<vector<int> > vvi;
typedef vector<vector<char> > vvc;
typedef vector<vector<bool> > vvb;
typedef vector<vector<double> > vvd;
typedef vector<vector<string> > vvs;
typedef vector<ll> vl;
typedef vector<vector<ll> > vvl;
typedef vector<vector<vector<ll> > > vvvl;
ll MOD = 1000000007;
const long long L_INF = 1LL << 60;
const int INF = 2147483647; // 2^31-1
const double PI = acos(-1);
//cout<<fixed<<setprecision(10);

template<class T> inline bool chmin(T& a, T b) {if (a > b) {a = b;return true;}return false;}
template<class T> inline bool chmax(T& a, T b) {if (a < b) {a = b;return true;}return false;}
template<class T> void debug(T v){rep(i,v.size()) cout<<v[i]<<" ";cout<<endl;}
const ll dx[8] = {1, 1, 0, -1, -1, -1, 0, 1};
const ll dy[8] = {0, 1, 1, 1, 0, -1, -1, -1};

struct BipartiteMatching {
  vector< vector< int > > graph;
  vector< int > match, alive, used;
  int timestamp;

  BipartiteMatching(int n) : graph(n), alive(n, 1), used(n, 0), match(n, -1), timestamp(0) {}

  void add_edge(int u, int v) {
    graph[u].push_back(v);
    graph[v].push_back(u);
  }

  bool dfs(int idx) {
    used[idx] = timestamp;
    for(auto &to : graph[idx]) {
      int to_match = match[to];
      if(alive[to] == 0) continue;
      if(to_match == -1 || (used[to_match] != timestamp && dfs(to_match))) {
        match[idx] = to;
        match[to] = idx;
        return true;
      }
    }
    return false;
  }

  int bipartite_matching() {
    int ret = 0;
    for(int i = 0; i < graph.size(); i++) {
      if(alive[i] == 0) continue;
      if(match[i] == -1) {
        ++timestamp;
        ret += dfs(i);
      }
    }
    return ret;
  }

  void output() {
    for(int i = 0; i < graph.size(); i++) {
      if(i < match[i]) {
        cout << i << "-" << match[i] << endl;
      }
    }
  }
};


signed main()
{
  gearup;
  int n; cin >> n;
  vpii r,b;
  rep(i,n){
    int x,y; cin >> x >> y;
    x--;y--;
    r.push_back({x,y});
  }
  rep(i,n){
    int x,y; cin >> x >> y;
    x--;y--;
    b.push_back({x,y});
  }
  //sort(all(r));
  //sort(all(b));
  
  BipartiteMatching bm(n + n);
  rep(i,n){
    rep(j,n){
      if(r[i].first < b[j].first && r[i].second < b[j].second) bm.add_edge(i,n+j);
    }
  }
  
  out(bm.bipartite_matching());
}
#include<bits/stdc++.h>

using namespace std;

#define LL long long
#define DD double
#define Pb push_back
#define Bp pop_back
#define Pf push_front
#define Fp pop_front
#define Ub upper_bound
#define Lb lower_bound
#define In insert
#define All(x) x.begin(), x.end()
#define mem(a, b) memset(a, b, sizeof(a))
#define fast ios_base::sync_with_stdio(0);cin.tie(0)
#define X first
#define Y second
#define mx1 10
#define mx2 110
#define mx3 1010
#define mx4 10010
#define mx5 100010
#define mx6 1000010

typedef vector<LL> Vl;
typedef vector<DD> Vd;
typedef vector<bool> Vb;
typedef vector<Vl> VVl;
typedef pair<LL, LL> Pll;
typedef pair<DD, DD> Pdd;
typedef vector<Pll> Vpl;
typedef vector<Pdd> Vpd;
typedef queue<LL> Ql;
typedef stack<LL> Sl;
typedef deque<LL> Dl;

LL _set(LL N, LL pos) {return N = N | (1 << pos);}
LL _reset(LL N, LL pos) {return N = N & ~(1 << pos);}
bool _check(LL N, LL pos) {return (bool)(N & (1 << pos));}
bool _upper(char a) {return a >= 'A' && a <= 'Z';}
bool _lower(char a) {return a >= 'a' && a <= 'z';}
bool _digit(char a) {return a >= '0' && a <= '9';}

LL dx[] = {1, -1, 0, 0, -1, -1, 1, 1};
LL dy[] = {0, 0, 1, -1, -1, 1, -1, 1};

///**************************DONE****************************///

typedef struct
{
    int x, y, col;
} pt;

bool cmp(pt A, pt B)
{
    if(A.x != B.x)
        return A.x < B.x;
}

pt P[2 * mx2];

int main()
{
    int n;
    cin >> n;

    for(int i = 0; i < n; i++)
        cin >> P[i].x >> P[i].y, P[i].col = 1;
    for(int i = n; i < 2 * n; i++)
        cin >> P[i].x >> P[i].y, P[i].col = 2;

    sort(P, P + 2 * n, cmp);

    priority_queue<int> pq;
    int ans = 0;
    for(int i = 0; i < 2 * n; i++){
        if(P[i].col == 2){
            if(pq.size() == 0)
                continue;

            queue<int> q;
            while(!pq.empty()){
                int t = pq.top();
                pq.pop();

                if(t < P[i].y){
                    ans++;
                    break;
                }

                q.push(t);
            }

            while(!q.empty()){
                int t = q.front();
                pq.push(t);
                q.pop();
            }
        }
        else
            pq.push(P[i].y);
    }

    cout << ans << '\n';
    return 0;
}
