#include <bits/stdc++.h>
using namespace std;
#define fo(a,b,c) for(int a=b;a<=c;a++)
#define of(a,b,c) for(int a=b;a>=c;a--)
const int N=5e4+10;
const int MINN=-0x3f3f3f3f;
struct Node1{
	int a,b;
}pl1[N];
struct Node2{
	int a,b;
}pl2[N];
bool cmp1(Node1 x,Node1 y){
	return x.a<y.a;
}
bool cmp2(Node2 x,Node2 y){
	return x.a<y.a;
}
priority_queue<int,vector<int>,greater<int> > Q1;
priority_queue<int,vector<int>,greater<int> > Q2;
inline int read(){
	int s=0,f=1;
	char ch=getchar();
	while(ch<'0'||ch>'9'){
		if(ch=='-'){
			f=-1;
			break;
		}
		ch=getchar();
	}
	while(ch>='0'&&ch<='9'){
		int u=ch^48;
		s=(s<<3)+(s<<1)+u;
		ch=getchar();
	}
	return s*f;
}
signed main(){
	int n;
	n=read();
	int m1,m2;
	m1=read();
	m2=read();
	fo(i,1,m1){
		pl1[i].a=read();
		pl1[i].b=read();
	}
	fo(i,1,m2){
		pl2[i].a=read();
		pl2[i].b=read();
	}
	int maxn=MINN;
	fo(i,0,n){
		stable_sort(pl1+1,pl1+m1+1,cmp1);
		int c1=i;
		int s1=0;
		int ans1=0;
		while(Q1.size()){
		    Q1.pop();
		}
		fo(j,1,m1){
			int u=Q1.top();
			while(Q1.size()&&pl1[j].a>=u){
				Q1.pop();
				u=Q1.top();
				--s1;
			}
			if(s1==c1){
				continue;
			}
			Q1.push(pl1[j].b);
			++s1;
			++ans1;
		}
		stable_sort(pl2+1,pl2+m2+1,cmp2);
		int c2=n-i;
		int s2=0;
		int ans2=0;
	    while(Q2.size()){
	        Q2.pop();
	    }
		fo(j,1,m2){
			int u=Q2.top();
			while(Q2.size()&&pl2[j].a>=u){
				Q2.pop();
				u=Q2.top();
				--s2;
			}
			if(s2==c2){
				continue;
			}
			Q2.push(pl2[j].b);
			++s2;
			++ans2;
		}
		int sum=ans1+ans2;
		if(sum>maxn){
			maxn=sum;
		}
		/*cout<<ans1<<" "<<ans2;
		cout<<endl;*/
	}
	cout<<maxn<<endl;
	return 0;
}