#include<bits/stdc++.h>
#define LL long long
using namespace std;
int f[5005][5005],al[5005],ar[5005],bl[5005],br[5005];
signed main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int n,as,bs;
	cin>>n>>as>>bs;
	for(int i=1;i<=n;i++) cin>>al[i]>>ar[i]>>bl[i]>>br[i];
	memset(f,-0x3f,sizeof(f));
	f[0][0]=0;
	for(int i=0;i<n;i++){
		for(int j=0;j<=n;j++){
			int ac=as+j,bc=bs+f[i][j];
			if(al[i+1]<=ac&&ac<=ar[i+1]&&bl[i+1]<=bc&&bc<=br[i+1]){
				f[i+1][j]=max(f[i+1][j],f[i][j]+1);
				f[i+1][j+1]=max(f[i+1][j+1],f[i][j]);
			}
			else f[i+1][j]=max(f[i+1][j],f[i][j]);
		}
	}
	int ans=0;
	for(int i=0;i<=n;i++) ans=max(ans,i+f[n][i]);
	cout<<ans<<'\n';
	return 0;
}