Go: package main

import (
	"bufio"
	"os"
	"strconv"
	"strings"
	"sort"
	"fmt"
)

var scanner = bufio.NewScanner(os.Stdin)

func main() {
	for scanner.Scan() {
		n, _ := strconv.Atoi(scanner.Text())
		if n == 0 {
			break
		}
		hr := make([]entry, 0)
		for i := 0; i < n; i++ {
			scanner.Scan()
			buf := strings.Split(scanner.Text(), " ")
			first, _ := strconv.Atoi(buf[0])
			second, _ := strconv.Atoi(buf[1])
			mt := entry{first, second}
			hr = append(hr, mt)
		}
		scanner.Scan()
		m, _ := strconv.Atoi(scanner.Text())
		for i := 0; i < m; i++ {
			scanner.Scan()
			buf := strings.Split(scanner.Text(), " ")
			first, _ := strconv.Atoi(buf[0])
			second, _ := strconv.Atoi(buf[1])
			mt := entry{first, second}
			hr = append(hr, mt)
		}
		sort.Sort(ByFirst(hr))
		fmt.Println(LIS(hr))
	}
}

type entry struct {
	first, second int
}

type ByFirst []entry

func(f ByFirst) Len() int {
	return len(f)
}

func (f ByFirst) Swap(i, j int) {
	f[i], f[j] = f[j], f[i]
}

func (f ByFirst) Less(i, j int) bool {
	return f[i].first < f[j].first
}

func LIS(hr []entry) int {
	n := len(hr)
	lis := make([]int, n)
	lis[n-1] = 1
	for i := n-2; i > -1; i-- {
		m := 0
		for j := i+1; j < n; j++ {
			if hr[i].first < hr[j].first && hr[i].second < hr[j].second && lis[j] > m {
				m = lis[j]
			}
		}
		lis[i] = m+1
	}
	return lis[0]
}

C++: #include <stdio.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <cctype>

#include <iostream>
#include <vector>
#include <deque>
#include <queue>
#include <map>
#include <algorithm>

using namespace std;

#define rep(i, n) for(int i = 0; i < n; i++)
#define repi(i,l,n) for(int (i)=(int)(l);(i)<(int)(n);(i)++)
#define d_arr(arr, h, w) rep(i,(h) ){ cout << "["; rep(j,(w) ) { cout << (arr)[i][j] << ", "; } cout << "]" << endl;}
#define IN(x,s,g) ((x) >= (s) && (x) < (g))
#define ISIN(x,y,w,h) (IN((x),0,(w)) && IN((y),0,(h)))
#define print(x) printf("%d\n",x);
#define fs first
#define sc second
#define pb push_back

typedef pair<int ,int> P;
vector<P> mv;
map<int, int> memo;

//
int next_of(int i){
    if( i == mv.size()-1 ) { return mv.size(); }
    else if( i >= mv.size()-1 ) { return mv.size(); }
    int h = mv[i].fs;
    int r = mv[i].sc;
    int nh = h;
    int nr = r;
    while(1){
        if( nh > h && nr > r) { break; }
        i++;
        nh = mv[i].fs;
        nr = mv[i].sc;
    }
    return i;
}

// mv[i] 以上で作れるマトリョーシカの数の最大値
int rec(int i){
    //cout << "rec : " << i << endl;
    if( memo.find(i) != memo.end() ){ return memo[i]; }
    if( i == mv.size() ){ return 0; }
    if( mv.size()-1 < i ){
        return 0;
    }
    int e0 = rec(i+1);
    int e1 = 0;
    int next = next_of(i);
    e1 = rec(next) + 1;
    memo[i] = max(e0,e1);
    return memo[i];
}

int main()
{
    int n,m;
    int h,r;
    while(1){
        mv.clear();
        memo.clear();
        cin >> n;
        if( n==0 ){ break; }
        rep(i,n){
            cin >> h >> r;
            mv.pb(make_pair(h,r));
        }
        cin >> m;
        rep(i,m){
            cin >> h >> r;
            mv.pb(make_pair(h,r));
        }
        sort(mv.begin(),mv.end());
        cout << rec(0) << endl;
    }
}

C++: #include <bits/stdc++.h>
 
using namespace std;
using ll = long long;
// #define int ll
using PII = pair<int, int>;
 
#define FOR(i, a, n) for (ll i = (ll)a; i < (ll)n; ++i)
#define REP(i, n) FOR(i, 0, n)
#define ALL(x) x.begin(), x.end()
 
template<typename T> T &chmin(T &a, const T &b) { return a = min(a, b); }
template<typename T> T &chmax(T &a, const T &b) { return a = max(a, b); }
template<typename T> bool IN(T a, T b, T x) { return a<=x&&x<b; }
template<typename T> T ceil(T a, T b) { return a/b + !!(a%b); }
 
template<typename T> vector<T> make_v(size_t a) { return vector<T>(a); }
template<typename T,typename... Ts>
auto make_v(size_t a,Ts... ts) { 
  return vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));
}
template<typename T,typename V> typename enable_if<is_class<T>::value==0>::type
fill_v(T &t, const V &v) { t=v; }
template<typename T,typename V> typename enable_if<is_class<T>::value!=0>::type
fill_v(T &t, const V &v ) { for(auto &e:t) fill_v(e,v); }
 
template<class S,class T>
ostream &operator <<(ostream& out,const pair<S,T>& a){
  out<<'('<<a.first<<','<<a.second<<')'; return out;
}
template<typename T>
istream& operator >> (istream& is, vector<T>& vec){
  for(T& x: vec) {is >> x;} return is;
}
template<class T>
ostream &operator <<(ostream& out,const vector<T>& a){
  out<<'['; for(T i: a) {out<<i<<',';} out<<']'; return out;
}
 
int dx[] = {0, 1, 0, -1}, dy[] = {1, 0, -1, 0}; // DRUL
const int INF = 1<<30;
const ll LLINF = 1LL<<60;
ll MOD = 1000000007;

template <typename T>
class BIT {
private:
  // データ
  vector<T> bit;
  // 単位元, 要素数
  int neutral = 0;
  // 更新クエリ, 区間クエリ
  function<T(T,T)> f = [](const T l, const T r) -> T { return r; },
                   g = [](const T l, const T r) -> T { return max(l, r); };
public:
  // 初期化
  BIT(int n_ = 1e5) { init(n_); }
  void init(int n_ = 1e5) { bit.assign(n_+1, neutral); }
  // iに対する点更新クエリ
  void update(int i, T w) {
    for(int x = i+1; x < bit.size(); x += x&-x) bit[x] = f(bit[x], w);
  }
  // [0,i]に対する区間クエリ
  T query(int i) {
    T ret = neutral;
    for(int x = i+1; x > 0; x -= x & -x) ret = g(ret, bit[x]);
    return ret;
  }
};

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

  while(1) {
    ll n;
    cin >> n;
    if(!n) break;
    vector<PII> v(n);
    REP(i, n) cin >> v[i].first >> v[i].second;
    ll m;
    cin >> m;
    REP(i, m) {
      ll h, r;
      cin >> h >> r;
      v.push_back({h, r});
    }

    sort(ALL(v), [](PII l, PII r){
      if(l.first != r.first) return l.first < r.first;
      return l.second > r.second;
    });

    ll ret = 0;
    BIT<ll> bit(1001);
    REP(i, n+m) {
      ll tmp = bit.query(v[i].second) + 1;
      bit.update(v[i].second, tmp);
      chmax(ret, tmp);
    }
    cout << ret << endl;
  }

  return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>

using namespace std;

typedef pair<int, int> P;

int main() {
	int n;
	while (cin >> n) {
		if (n == 0) {
			break;
		}
		vector<P> dd;
		int h, r;
		for (int i = 0; i < n; i++) {
			cin >> h >> r;
			dd.push_back(P(h, r));
		}
		int m;
		cin >> m;
		for (int i = 0; i < m; i++) {
			cin >> h >> r;
			dd.push_back(P(h, r));
		}
		sort(dd.begin(), dd.end());
		int MAX = 0;
		vector<int> dp(n+m, 1);
		for (int i = 1; i < n+m; i++) {
			for (int j = 0; j < i; j++) {
				if (dd[j].first < dd[i].first && dd[j].second < dd[i].second) {
					dp[i] = max(dp[i], dp[j]+1);
				}
			}
			MAX = max(MAX, dp[i]);
		}
		cout << MAX << endl;
	}
	return 0;
}