[POJ3614]Sunscreen[贪心]

#include<cstdio>
#include<algorithm>
#define in inline
#define re register
#define int long long
using namespace std;
in int read()
{
	int s(0),b(0);char ch;
	do{ch=getchar();if(ch=='-')b=1;}while(ch<'0'||ch>'9');
	while(ch>='0'&&ch<='9') s=(s<<3)+(s<<1)+(ch^48),ch=getchar();
	if(b) return -s;
	return s;
}
int n,m;
struct COW{
	int mins,maxs;
	bool operator<(const COW &t){return mins>t.mins;}
}cow[2600];
struct LO{
	int s,c;
	bool operator<(const LO &t){return s>t.s;}
}lo[2600];
signed main()
{
	n=read(),m=read();
	for(re int i=1;i<=n;++i) cow[i].mins=read(),cow[i].maxs=read();
	for(re int i=1;i<=m;++i) lo[i].s=read(),lo[i].c=read();
	sort(cow+1,cow+n+1);
	sort(lo+1,lo+m+1);
	int ans=0;
	for(re int i=1;i<=n;++i)
	{
		for(re int j=1;j<=m;++j)
		{
			if(lo[j].s>=cow[i].mins&&lo[j].s<=cow[i].maxs&&lo[j].c>0)
			{--lo[j].c,++ans;break;}
		}
	}
	printf("%lld\n",ans);
	return 0;
}