#include<bits/stdc++.h>
#define Gc() getchar()
#define Me(x,y) memset(x,y,sizeof(x))
#define Mc(x,y) memcpy(x,y,sizeof(x))
#define d(x,y) ((m)*(x-1)+(y))
#define R(n) (rnd()%(n)+1)
#define Pc(x) putchar(x)
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define eb emplace_back
#define all(x) x.begin(),x.end()
using namespace std;using ll=long long;using db=double;using lb=long db;using ui=unsigned;using ull=unsigned long long;using pii=pair<int,int>;
const int N=5000+5,M=N*60+5,K=1000+5,mod=912491249,Mod=mod-1;const db eps=1e-9;const int INF=1e9+7;mt19937 rnd(263082);
#define Tp template<typename T>
#define Ts template<typename T,typename... Ar>
namespace Debug{
	Tp void _debug(char* f,T t){cerr<<f<<'='<<t<<endl;}
	Ts void _debug(char* f,T x,Ar... y){while(*f!=',') cerr<<*f++;cerr<<'='<<x<<",";_debug(f+1,y...);}
	#ifdef LOCAL
	#define gdb(...) _debug((char*)#__VA_ARGS__,__VA_ARGS__)
	#else 
	#define gdb(...) void()
	#endif
}using namespace Debug;
int n,sx,sy;
bitset<N> g,dp[N];
void Solve(){
	int i,j;scanf("%d%d%d",&n,&sx,&sy);
	int maxx=0;dp[0][0]=1;
	for(i=1;i<=n;i++){
		int lx,ly,rx,ry;scanf("%d%d%d%d",&lx,&rx,&ly,&ry);
		g.reset();
		for(int j=0;j<=n;j++) if(ly<=j+sy&&j+sy<=ry) g[j]=1;
		for(int j=maxx;~j;j--) if(lx<=sx+j&&sx+j<=rx){
			if(j==maxx) maxx++;
			dp[j+1]|=dp[j];
			dp[j]|=(dp[j]&g)<<1;
		}
	}
	int ans=0;
	for(i=0;i<=n;i++) for(j=0;j<=n;j++) if(dp[i][j]) ans=max(ans,i+j);
	printf("%d\n",ans);
}
int main(){
	int t=1;
	// scanf("%d",&t);
	while(t--) Solve();
	cerr<<clock()*1.0/CLOCKS_PER_SEC<<'\n';
}