#include<bits/stdc++.h>
using namespace std;

const int N=5005;
int n,a,b,la[N],ra[N],lb[N],rb[N];

typedef bitset<N> bs;
bs dp[2][N];
int main(){
	scanf("%d%d%d",&n,&a,&b);
	for(int i=1;i<=n;i++){
		scanf("%d%d%d%d",&la[i],&ra[i],&lb[i],&rb[i]);
		la[i]=max(0,la[i]-a);
		ra[i]=min(n-1,ra[i]-a);
		lb[i]=max(0,lb[i]-b);
		rb[i]=min(n-1,lb[i]-b);
	}
	dp[0][0].set(0);
	for(int i=1;i<=n;i++){
		bool o=i&1;
		if(la[i]>ra[i]||lb[i]>rb[i])continue;
		for(int j=0;j<n;j++)dp[o][j]=dp[!o][j];
		for(int j=la[i];j<=ra[i];j++){
			bs tmp=dp[!o][j];
			tmp>>=lb[i];
			tmp<<=N-rb[i]+lb[i]-1;
			tmp>>=N-rb[i]-1;
			dp[o][j+1]|=tmp;dp[o][j]|=tmp<<1;
		}
	}
	int res=0;
	for(int j=0;j<n;j++)for(int k=0;k<n;k++)if(dp[n&1][j][k])res=max(res,j+k);
	printf("%d\n",res);
	return 0;
}