//start of jonathanirvings' template v3.0.3 (BETA)

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

typedef long long LL;
typedef pair<int,int> pii;
typedef pair<LL,LL> pll;
typedef pair<string,string> pss;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pii> vii;
typedef vector<LL> vl;
typedef vector<vl> vvl;

double EPS = 1e-9;
int INF = 1000000005;
long long INFF = 1000000000000000005LL;
double PI = acos(-1);
int dirx[8] = {-1,0,0,1,-1,-1,1,1};
int diry[8] = {0,1,-1,0,-1,1,-1,1};

#ifdef TESTING
  #define DEBUG fprintf(stderr,"====TESTING====\n")
  #define VALUE(x) cerr << "The value of " << #x << " is " << x << endl
  #define debug(...) fprintf(stderr, __VA_ARGS__)
#else
  #define DEBUG 
  #define VALUE(x)
  #define debug(...)
#endif

#define FOR(a,b,c) for (int (a)=(b);(a)<(c);++(a))
#define FORN(a,b,c) for (int (a)=(b);(a)<=(c);++(a))
#define FORD(a,b,c) for (int (a)=(b);(a)>=(c);--(a))
#define FORSQ(a,b,c) for (int (a)=(b);(a)*(a)<=(c);++(a))
#define FORC(a,b,c) for (char (a)=(b);(a)<=(c);++(a))
#define FOREACH(a,b) for (auto &(a) : (b))
#define REP(i,n) FOR(i,0,n)
#define REPN(i,n) FORN(i,1,n)
#define MAX(a,b) a = max(a,b)
#define MIN(a,b) a = min(a,b)
#define SQR(x) ((LL)(x) * (x))
#define RESET(a,b) memset(a,b,sizeof(a))
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define ALL(v) v.begin(),v.end()
#define ALLA(arr,sz) arr,arr+sz
#define SIZE(v) (int)v.size()
#define SORT(v) sort(ALL(v))
#define REVERSE(v) reverse(ALL(v))
#define SORTA(arr,sz) sort(ALLA(arr,sz))
#define REVERSEA(arr,sz) reverse(ALLA(arr,sz))
#define PERMUTE next_permutation
#define TC(t) while(t--)

inline string IntToString(LL a){
  char x[100];
  sprintf(x,"%lld",a); string s = x;
  return s;
}

inline LL StringToInt(string a){
  char x[100]; LL res;
  strcpy(x,a.c_str()); sscanf(x,"%lld",&res);
  return res;
}

inline string GetString(void){
  char x[1000005];
  scanf("%s",x); string s = x;
  return s;
}

inline string uppercase(string s){
  int n = SIZE(s); 
  REP(i,n) if (s[i] >= 'a' && s[i] <= 'z') s[i] = s[i] - 'a' + 'A';
  return s;
}

inline string lowercase(string s){
  int n = SIZE(s); 
  REP(i,n) if (s[i] >= 'A' && s[i] <= 'Z') s[i] = s[i] - 'A' + 'a';
  return s;
}

inline void OPEN (string s) {
  #ifndef TESTING
  freopen ((s + ".in").c_str (), "r", stdin);
  freopen ((s + ".out").c_str (), "w", stdout);
  #endif
}

//end of jonathanirvings' template v3.0.3 (BETA)

int n,x,y;
pair<pii,pii> data[200005];
pii P[200005];
int p[200005];

vector<int> pos[800005];
vector<LL> val[800005];
int sz[800005];

void preassign(int ix,int L,int R,int x)
{
  ++sz[ix];
  if (L == R) return;
  int M = (L + R) >> 1;
  if (x <= M) preassign(ix*2+1,L,M,x);
  else preassign(ix*2+2,M+1,R,x);
}

void assign(int ix,int L,int R,int x,int y)
{
  // pos[ix].pb(y);
  --sz[ix];
  pos[ix][sz[ix]] = y;
  if (L == R) return;
  int M = (L + R) >> 1;
  if (x <= M) assign(ix*2+1,L,M,x,y);
  else assign(ix*2+2,M+1,R,x,y);
}

inline void update1D(int ix1,int ix2,int L,int R,int y,LL v)
{
  // debug("<<<<<<%d %d %d %d %d %lld\n",ix1,ix2,L,R,y,v);
  MAX(val[ix1][ix2],v);
  if (L == R) return;
  int M = (L + R) >> 1;
  if (y <= pos[ix1][M]) update1D(ix1,ix2*2+1,L,M,y,v);
  else update1D(ix1,ix2*2+2,M+1,R,y,v);
}

inline void update2D(int ix,int L,int R,int x,int y,LL v)
{
  // debug("<<%d %d %d %d %d %lld\n",ix,L,R,x,y,v);
  // int temp = lower_bound(ALL(pos[ix]),y) - pos[ix].begin();
  update1D(ix,0,0,SIZE(pos[ix])-1,y,v);
  if (L == R) return;
  int M = (L + R) >> 1;
  if (x <= M) update2D(ix*2+1,L,M,x,y,v);
  else update2D(ix*2+2,M+1,R,x,y,v);
}

inline LL query1D(int ix1,int ix2,int L,int R,int ya,int yb)
{
  // debug(">>>>>%d %d %d %d %d %d\n",ix1,ix2,L,R,ya,yb);
  if (ya <= pos[ix1][L] && pos[ix1][R] <= yb) return val[ix1][ix2];
  if (pos[ix1][R] < ya || yb < pos[ix1][L]) return 0;
  int M = (L + R) >> 1;
  return max(query1D(ix1,ix2*2+1,L,M,ya,yb),query1D(ix1,ix2*2+2,M+1,R,ya,yb));
}

inline LL query2D(int ix,int L,int R,int xa,int xb,int ya,int yb)
{
  // debug(">>%d %d %d %d %d %d %d\n",ix,L,R,xa,xb,ya,yb);
  if (xa <= L && R <= xb)
  {
    if (pos[ix].empty()) return 0;
    // if (tempa > tempb) return 0;
    return query1D(ix,0,0,SIZE(pos[ix])-1,ya,yb);
  }
  if (R < xa || xb < L) return 0;
  int M = (L + R) >> 1;
  return max(query2D(ix*2+1,L,M,xa,xb,ya,yb),query2D(ix*2+2,M+1,R,xa,xb,ya,yb));
}

bool f(pair<pii,pii> a, pair<pii,pii> b)
{
  return a.se.se > b.se.se;
}

int main()
{
  scanf("%d %d %d",&n,&x,&y);
  REP(i,n)
  {
    scanf("%d %d %d %d",&data[i].se.fi,&data[i].se.se,&data[i].fi.fi,&data[i].fi.se);
  }
  sort(ALLA(data,n),f);
  REP(i,n) preassign(0,0,200000,data[i].se.fi);
  FORN(i,0,800000)
  {
    // SORT(pos[i]);
    pos[i].resize(sz[i]);
    val[i].resize(sz[i]*4);
  }
  REP(i,n) assign(0,0,200000,data[i].se.fi,data[i].se.se);
  SORTA(data,n);
  REP(i,n)
  {
    P[i] = data[i].se;
    p[i] = data[i].fi.se;
  }
  // REP(i,n) assign(0,0,200000,P[i].fi,P[i].se);
  // FORN(i,0,800000)
  // {
  //   // SORT(pos[i]);
  //   val[i].resize(SIZE(pos[i])*4);
  // }
  LL risan = 0;
  // return 0;
  FORD(i,n-1,0)
  {
    // VALUE(i);
    int xa = max(0,P[i].fi-x);
    int xb = min(200000,P[i].fi+x);
    int ya = max(0,P[i].se-y);
    int yb = min(200000,P[i].se+y);
    LL temp = query2D(0,0,200000,xa,xb,ya,yb);
    // VALUE(temp);
    temp += p[i];
    MAX(risan,temp);
    update2D(0,0,200000,P[i].fi,P[i].se,temp);
  }
  printf("%lld\n",risan);
  return 0;
}