#include <bits/stdc++.h>
#define SORT(a) sort(a.begin(), a.end())
#define RSORT(a) sort(a.rbegin(), a.rend())
#define REP(i, n) for (int i = 0; i < n; i++)
#define RREP(i, n) for (int i = n - 1; 0 <= i; i--)
#define FOR(i, start, end) for (int i = start; i < end; i++)
#define RFOR(i, start, end) for (int i = start - 1; 0 <= i; i--)
#define ALL(a) a.begin(), a.end()
using ll = long long;
using namespace std;
constexpr int INF32       = 1'050'000'000;
constexpr long long INF64 = 4'000'000'000'000'000'000;
constexpr int MOD7        = 1'000'000'007;
constexpr int MOD9        = 1'000'000'009;
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;
}
void print() { std::cout << '\n'; }
template <class H, class... T> void print(H &&head, T &&... args) {
    std::cout << head;
    sizeof...(args) == 0 ? std::cout << "" : std::cout << ' ';
    print(std::forward<T>(args)...);
}
template <class T> void print(std::vector<T> &v) {
    for (int i = 0; i < v.size(); i++) {
        std::cout << v[i];
        i == v.size() - 1 ? std::cout << '\n' : std::cout << ' ';
    }
}
template <class T> void print(std::vector<std::vector<T>> &v) {
    for (int i = 0; i < v.size(); i++) {
        for (int j = 0; j < v[i].size(); j++) {
            std::cout << v[i][j];
            j == v[i].size() - 1 ? std::cout << '\n' : std::cout << ' ';
        }
    }
}
void debug() { std::cerr << '\n'; }
template <class H, class... T> void debug(H &&head, T &&... args) {
    std::cerr << head;
    sizeof...(args) == 0 ? std::cerr << "" : std::cerr << ' ';
    debug(std::forward<T>(args)...);
}
template <class T> void debug(std::vector<T> &v) {
    for (int i = 0; i < v.size(); i++) {
        std::cerr << v[i];
        i == v.size() - 1 ? std::cerr << '\n' : std::cerr << ' ';
    }
}
template <class T> void debug(std::vector<std::vector<T>> &v) {
    for (int i = 0; i < v.size(); i++) {
        for (int j = 0; j < v[i].size(); j++) {
            std::cerr << v[i][j];
            j == v[i].size() - 1 ? std::cerr << '\n' : std::cerr << ' ';
        }
    }
}
template <class T1, class T2> void debug(std::pair<T1, T2> &x) {
    cerr << x.first << " " << x.second << '\n';
}

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);

    int N;
    cin >> N;
    vector<pair<int, int>> red(N), ble(N);
    for (auto &&i : red) {
        cin >> i.first >> i.second;
    }
    for (auto &&i : ble) {
        cin >> i.first >> i.second;
    }

    SORT(ble);
    sort(ALL(red), [](const pair<int, int> &x, const pair<int, int> &y) {
        return x.second > y.second;
    });
    int ans = 0;

    debug("-----");
    for (auto &&i : red) {
        debug(i);
    }
    debug("-----");
    for (auto &&i : ble) {
        debug(i);
    }

    REP(i, N) {
        int ax = red[i].first;
        int ay = red[i].second;
        REP(j, ble.size()) {
            int bx = ble[j].first;
            int by = ble[j].second;
            if (ax < bx && ay < by) {
                ans++;
                ble.erase(ble.begin() + j);
                break;
            }
        }
    }
    print(ans);

    return 0;
}

Measured memory_bytes: 256