#include <bits/stdc++.h>

template <typename T, typename _ = void>
struct is_container : std::false_type {};
template <typename T>
struct is_container<T, std::void_t<decltype(std::declval<T>().begin()),
                                   decltype(std::declval<T>().end())>>
    : std::true_type {};
template <typename T, typename _ = void>
struct is_pair : std::false_type {};
template <typename T>
struct is_pair<T, std::void_t<decltype(std::declval<T>().first),
                              decltype(std::declval<T>().second)>>
    : std::true_type {};
template <typename T>
void debug(const T& v) {
  if constexpr (is_pair<T>::value) {
    std::cerr << "{";
    debug(v.first);
    std::cerr << ", ";
    debug(v.second);
    std::cerr << "}";
  } else if constexpr (is_container<T>::value) {
    std::cerr << "{";
    for (auto it = v.begin(); it != v.end(); ++it) {
      if (it != v.begin()) std::cerr << ", ";
      debug(*it);
    }
    std::cerr << "}";
  } else {
    std::cerr << v;
  }
}
template <typename T, typename... Ts>
void debug(const T& value, const Ts&... args) {
  debug(value);
  std::cerr << ", ";
  debug(args...);
}
#if DEBUG
#define dbg(...)                        \
  do {                                  \
    cerr << #__VA_ARGS__ << ": ";       \
    debug(__VA_ARGS__);                 \
    cerr << " (L" << __LINE__ << ")\n"; \
  } while (0)
#else
#define dbg(...)
#endif

void read_from_cin() {}
template <typename T, typename... Ts>
void read_from_cin(T& value, Ts&... args) {
  std::cin >> value;
  read_from_cin(args...);
}
#define rd(type, ...) \
  type __VA_ARGS__;   \
  read_from_cin(__VA_ARGS__);

template <typename T>
void write_to_cout(const T& value) {
  if constexpr (std::is_same<T, bool>::value) {
    std::cout << (value ? "Yes" : "No");
  } else {
    std::cout << value;
  }
}
template <typename T, typename... Ts>
void write_to_cout(const T& value, const Ts&... args) {
  write_to_cout(value);
  std::cout << ' ';
  write_to_cout(args...);
}
#define wt(...)                 \
  do {                          \
    write_to_cout(__VA_ARGS__); \
    cout << '\n';               \
  } while (0)

#define all(x) (x).begin(), (x).end()
#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
#define rrep(i, n) for (int i = (int)(n)-1; i >= 0; --i)

template <typename T>
std::istream& operator>>(std::istream& is, std::vector<T>& v) {
  for (T& vi : v) is >> vi;
  return is;
}

template <typename T, typename U>
bool chmax(T& a, U b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}

template <typename T, typename U>
bool chmin(T& a, U b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}

#include <boost/hana/functional/fix.hpp>
auto Fix = boost::hana::fix;

using ll = long long;

template <typename T>
using low_priority_queue =
    std::priority_queue<T, std::vector<T>, std::greater<T>>;

template <typename T>
using V = std::vector<T>;
template <typename T>
using VV = V<V<T>>;

using namespace std;

struct XY {
  int x, y;
  bool operator<(const XY& xy) const {
    if (x != xy.x) return x < xy.x;
    return y < xy.y;
  }
};

int main() {
  rd(int, n);
  V<XY> r(n), b(n);
  rep(i, n) cin >> r[i].x >> r[i].y;
  rep(i, n) cin >> b[i].x >> b[i].y;
  sort(all(r));
  sort(all(b));
  int ans = 0;
  set<int> ry;
  auto ri = r.begin(), bi = b.begin();
  rep(x, 2 * n) {
    for (; ri != r.end() && ri->x <= x; ++ri) {
      ry.insert(ri->y);
    }
    for (; bi != b.end() && bi->x <= x; ++bi) {
      auto it = ry.lower_bound(bi->y);
      if (it != ry.begin()) {
        --it;
        ry.erase(it);
        ++ans;
      }
    }
  }
  wt(ans);
}


Measured memory_bytes: 3644