#include<stdio.h>
#include<algorithm>
struct pear
{
	int s, e;
	friend bool operator < (pear a, pear b)
	{
		return a.e<b.e;
	}
};
using namespace std;
int n, m;
pear a[2100];
int cnt[2100];
bool used[2100];
int ans;
int main()
{
	int i, k;
	int e, c;
	scanf("%d", &n);
	for(i=1;i<=n;i++) scanf("%d%d", &a[i].s, &a[i].e);
	scanf("%d", &m);
	for(i=1;i<=m;i++){scanf("%d%d", &e, &c); cnt[e]+=c;}
	sort(&a[1], &a[n+1]);
	for(k=1;k<=1000;k++)
	{
		for(i=1;i<=n && cnt[k];i++)
		{
			if(used[i] || k<a[i].s || a[i].e<k) continue;
			used[i]=true; ans++; cnt[k]--;
		}
	}
	printf("%d\n", ans);
	return 0;
}