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

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;

int main(){
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	cout<<setprecision(32);

	int n; cin>>n;
	set<pair<int, int> > a, b;
	for(int i = 0; i < n; i++){
		int x, y;
		cin>>x>>y;
		a.insert({x, y});
	}
	for(int i = 0; i < n; i++){
		int x, y;
		cin>>x>>y;
		b.insert({x, y});
	}
	int ans = 0;
	for(auto pp : b){
		int x = -1, y = -1;
		for(auto qq : a){
			if(qq.first < pp.first && qq.second < pp.second){
				if(y < qq.second){
					x = qq.first;
					y = qq.second;
				}
			}
		}
		if(x != -1){
			a.erase({x, y});
			ans++;
		}
	}
	cout<<ans<<endl;

	return 0;
}
#include <bits/stdc++.h>
  
using namespace std;
  
template<class T> void ckmin(T &a, T b) { a = min(a, b); }
template<class T> void ckmax(T &a, T b) { a = max(a, b); }
  
#define pb push_back
#define mp make_pair
#define cotu cout
#define itn int
#define Red ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define F first
#define S second
#define sz(x) (int)x.size()
#define all(x) (x).begin(), (x).end()
#define rep(i, n) for(int i = 0; i < n; ++i)
#define repr(i,n) for(int i = n - 1; i >= 0; --i)
#define Rep(i, a, n) for(int i = (a); i <=(n); ++i)
#define repst(i, n) for(auto it = n.begin(); it != n.end(); ++it)
#define Repr(i, a, n) for(int i = (n); i >= (a); --i)
#define setp(x) fixed << setprecision(x)
#define ordered_set tree<int , null_type,less<int >, rb_tree_tag,tree_order_statistics_node_update> 
  
#include <ext/pb_ds/assoc_container.hpp> 
#include <ext/pb_ds/tree_policy.hpp> 
using namespace __gnu_pbds; 
  
typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
  
const int inf = int(1e9);
const int mod = inf + 7;
const int N = 3e5 + 555; // TL MB
const double PI = acos(-1.0);
void mul(ll &x, ll y){
	x *= y;
	if(x >= mod) x %= mod;
}
 
void add(ll &x, ll y){
	x += y;
	if(x >= mod) x -= mod;
	if(x < 0) x += mod;
}
ll bp(ll a, ll n){
	ll r = 1;
	while(n){
		if(n & 1) mul(r, a);
		mul(a, a);
		n >>= 1;
	}
	return r; 
}

vector<int> g[N];
int n, k;
vector<int> mt;
vector<char> used;
 
bool try_kuhn (int v) {
	if (used[v])  return false;
	used[v] = true;
	for (size_t i=0; i<g[v].size(); ++i) {
		int to = g[v][i];
		if (mt[to] == -1 || try_kuhn (mt[to])) {
			mt[to] = v;
			return true;
		}
	}
	return false;
}
 

void solve()
{
		cin >> n;
		vector<pii> p(n), q(n);
		rep(i, n) cin >> p[i].F >> p[i].S;
		rep(i, n) cin >> q[i].F >> q[i].S;
		sort(all(p));
		sort(all(q));
		rep(i, sz(p)){
			rep(j, sz(q)){
				if(p[i].F < q[j].F && p[i].S < q[j].S) g[i].pb(j + n), g[j + n].pb(i);
			}
		}
	k = 2 * n;
	mt.assign (k, -1);
	for (int v=0; v<n; ++v) {
		used.assign (n, false);
		try_kuhn (v);
	}
 
 	int res = 0;
	for (int i=n; i<2*n; ++i)
		if (mt[i] != -1) ++res;
	cout << res;
}

int main()
{
	// freopen("input.txt", "r", stdin);
	// freopen("output.txt", "w", stdout);
    // Red;
  	int T = 1;
  	// cin >> T;
  	for(int i = 1; i <= T; ++i){
  		solve();
  	}
  	return 0;

}