#include<stdio.h>
#include<set>
#include<stdlib.h>
#include<algorithm>
using namespace std;
#define nmax 50005
struct punct{int x,y;};
int n, i, poz, rez, x, ne[5];
punct v[5][nmax];
set <int> h;
set <int> ::iterator it;
punct p,o;

bool cmp(punct a, punct b)
{   return (a.y<b.y);   }

void citire()
{
    scanf("%ld",&n);
    scanf("%ld %ld",&o.x,&o.y);
    for (i=1;i<=n;i++)
    {
        scanf("%ld %ld",&p.x,&p.y);
        poz=2*(p.x>o.x)+(p.y>o.y);
        p.x=abs(p.x-o.x);   p.y=abs(p.y-o.y);
        v[poz][++ne[poz]]=p;
    }
}

void rezolvare()
{
    sort(v[poz]+1,v[poz]+1+ne[poz],cmp);
    h.clear();
    for (i=1;i<=ne[poz];i++)
    {
        x=v[poz][i].x;
        it=h.upper_bound(x);
        if (it==h.begin())
            rez++;
        else
        {
            it--;
            h.erase(it);
        }
        h.insert(x);
    }
}

int main()
{
    freopen("pachete.in","r",stdin);
    freopen("pachete.out","w",stdout);
    citire();
    for (poz=0;poz<=3;poz++)
        rezolvare();
    printf("%ld",rez);
    return 0;
}