#include <algorithm>
#include <bitset>
#include <cmath>
#include <cstring>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <regex>
#include <set>
#include <stack>
#include <string>
#include <vector>

const int MOD = 1e9 + 7;
const int iINF = 2147483647 / 2;
const long long int llINF = 9223372036854775807 / 2;

using namespace std;
using ll = long long int;
using vl = vector<ll>;
using vvl = vector<vector<ll>>;
using vvvl = vector<vector<vector<ll>>>;

typedef pair<ll, ll> pll;
bool paircomp(const pll &a, const pll &b) {
  if (a.first == b.first)
    return a.second < b.second;
  return a.first < b.first;
}
struct multi {
  ll first;
  ll second;
  ll third;
  multi(ll first, ll second, ll third)
      : first(first), second(second), third(third) {}
};
bool multicomp(const multi &a, const multi &b) {
  if (a.first == b.first)
    return a.second < b.second;
  return a.first < b.first;
}
#define REP(i, n) for (ll i = 0; i < (n); i++)
#define RREP(i, n) for (ll i = (n)-1; i >= 0; i--)
#define FOR(i, a, b) for (ll i = (a); i < (b); i++)
#define AUTO(i, m) for (auto &i : m)
#define ALL(a) (a).begin(), (a).end()
#define MAX(vec) *std::max_element(vec.begin(), vec.end())
#define MIN(vec) *std::min_element(vec.begin(), vec.end())
#define ARGMAX(vec)                                                            \
  std::distance(vec.begin(), std::max_element(vec.begin(), vec.end()))
#define ARGMIN(vec)                                                            \
  std::distance(vec.begin(), std::min_element(vec.begin(), vec.end()))
#define REV(T) greater<T>()
#define PQ(T) priority_queue<T, vector<T>, greater<T>>
#define VVL(a, b, c) vector<vector<ll>>(a, vector<ll>(b, c))
#define VVVL(a, b, c, d)                                                       \
  vector<vector<vector<ll>>>(a, vector<vector<ll>>(b, vector<ll>(c, d)))
#define SP(a) setprecision(a)
#define SQRT(a) sqrt((long double)(a))
#define DPOW(a, b) pow((long double)(a), (long double)(b))
#define UNIQUE(vec)                                                            \
  do {                                                                         \
    sort(ALL((vec)));                                                          \
    (vec).erase(std::unique(ALL((vec))), (vec).end());                         \
  } while (0)

ll POW(ll n, ll m) {
  if (m == 0) {
    return 1;
  } else if (m % 2 == 0) {
    ll tmp = POW(n, m / 2);
    return (tmp * tmp);
  } else {
    return (n * POW(n, m - 1));
  }
}

int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};

typedef ll Weight;
struct Edge {
  ll src, dst;
  Weight weight;
  Edge(ll src, ll dst, Weight weight) : src(src), dst(dst), weight(weight) {}
};
bool operator<(const Edge &e, const Edge &f) {
  return e.weight != f.weight ? e.weight > f.weight : // !!INVERSE!!
             e.src != f.src ? e.src < f.src : e.dst < f.dst;
}
typedef vector<Edge> Edges;
typedef vector<Edges> Graph;

bool augment(const Graph &g, ll u, vector<ll> &matchTo, vector<bool> &visited) {
  if (u < 0)
    return true;
  AUTO(e, g[u]) if (!visited[e.dst]) {
    visited[e.dst] = true;
    if (augment(g, matchTo[e.dst], matchTo, visited)) {
      matchTo[e.src] = e.dst;
      matchTo[e.dst] = e.src;
      return true;
    }
  }
  return false;
}
ll bipartiteMatching(const Graph &g, ll L) {
  const ll n = g.size();
  vector<ll> matchTo(n, -1);
  ll match = 0;
  REP(u, L) {
    vector<bool> visited(n);
    if (augment(g, u, matchTo, visited))
      ++match;
  }
  return match;
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  ll N;
  cin >> N;
  vector<pll> A(N), B(N);
  Graph g(2 * N);

  REP(i, N) {
    ll a, b;
    cin >> a >> b;
    A[i] = make_pair(a, b);
  }
  // sort(ALL(A));
  REP(i, N) {
    ll a, b;
    cin >> a >> b;
    B[i] = make_pair(a, b);
  }
  // sort(ALL(B));

  REP(ai, N) REP(bi, N) {
    if (A[ai].first < B[bi].first && A[ai].second < B[bi].second) {
      g[ai].push_back(Edge(ai, N + bi, 1));
      g[N + bi].push_back(Edge(N + bi, N + ai, 1));
    }
  }
  cout << bipartiteMatching(g, N) << endl;

  return 0;
}


Measured memory_bytes: 512