#include <cstdio>
#include <algorithm>
#include <vector>
using namespace std;
#define INF 0x3f3f3f3f

struct P{
	long long x,y;
};

vector<P> C1,C2,C3,C4;
long long Q[50005];

struct comp{
	bool operator()(const P &a,const P &b){
		if(a.x == b.x) return a.y < b.y;
		return a.x < b.x;
	}
};

long long Rez_cadran(vector<P> A){
	int N = A.size();
	sort(A.begin(),A.end(),comp());
	
	long long Best = 0;
	for(int i = N - 1; i >= 0; i--){
		Q[N-i] = INF;
		int p = lower_bound(Q+1,Q+N-i+1,A[i].y) - Q;
		Q[p] = A[i].y;
		if(Best < p) Best = p;
	}
	return Best;
}

int main(){

	freopen("pachete.in", "r", stdin);
	freopen("pachete.out", "w", stdout);

	int n,X,Y;
	scanf("%d\n%d%d",&n,&X,&Y);
	for(int i = 1; i <= n; i++){
		P a;
		scanf("%lld%lld",&a.x,&a.y);
		if(a.x > X && a.y > Y){ 
			C1.push_back(a);
		}
		else if(a.x < X && a.y > Y){
			a.x = X - a.x + X;
			C2.push_back(a);
		}
		else if(a.x < X && a.y < Y){
			a.x = X - a.x + X;
			a.y = Y - a.y + Y; 
			C3.push_back(a);
		}
		else{
			a.y = Y - a.y + Y;
			C4.push_back(a);
		}
	}
	
	long long Ans = 0;
	Ans += Rez_cadran(C1);
	Ans += Rez_cadran(C2);	
        Ans += Rez_cadran(C3);
        Ans += Rez_cadran(C4);
	
	printf("%lld\n",Ans);
}