#include<bits/stdc++.h>
#define int long long
#define ull unsigned long long
#define p_b push_back
#define m_p make_pair
#define pii pair<int,int> 
#define fi first
#define se second
#define ls k<<1
#define rs k<<1|1
#define mid ((l+r)>>1)
using namespace std;
inline int rd(){
	int x=0,f=1; char ch=getchar();
	for(;ch<'0'||ch>'9';ch=getchar())if (ch=='-') f=-1;
	for(;ch>='0'&&ch<='9';ch=getchar())x=(x<<1)+(x<<3)+(ch^48);
	return x*f;
}
const int N=5005,INF=0x3f3f3f3f3f3f3f3f;
bool f[N][N];
int l1[N],r1[N],l2[N],r2[N];
int n,a,b;
set<int> s[N];
vector<pii> vec;
signed main(){
	n=rd(),a=rd(),b=rd();
	for(int i=1;i<=n;i++){
		l1[i]=rd()-a,r1[i]=rd()-a,l2[i]=rd()-b,r2[i]=rd()-b;
		l1[i]=max(0ll,l1[i]),r1[i]=max(0ll,r1[i]);
		//l2[i]=max(0ll,l2[i]),r2[i]=max(0ll,r2[i]);
		r1[i]=min(r1[i],n),r2[i]=min(r2[i],n);
	}
	f[0][0]=1,s[0].insert(0);
	for(int i=1;i<=n;i++){
		vec.clear();
		for(int j=l1[i];j<=r1[i];j++){
			auto it=s[j].lower_bound(l2[i]);
			for(;it!=s[j].end()&&*it<=r2[i];){
				int k=*it;it=s[j].erase(it);
				if(!f[j][k+1]) f[j][k+1]=1,vec.p_b(m_p(j,k+1));
				if(!f[j+1][k]) f[j+1][k]=1,vec.p_b(m_p(j+1,k));
			}
		}
		for(auto x : vec) s[x.fi].insert(x.se);
	}
	int ans=-INF;
	for(int i=0;i<=n;i++)for(int j=0;j<=n;j++) if(f[i][j]) ans=max(ans,i+j);
	printf("%lld\n",ans);
	return 0;	
}