///TEST

#include <bits/stdc++.h>

using namespace std;

ifstream f("pachete.in");
ofstream g("pachete.out");

int n,ox,oy,i,j,nrd;

struct str{
    int x,y;
    bool fol;
}v[50001];

bool cond(str a, str b){
    if(a.x!=b.x)
        return a.x<b.x;
    return a.y<b.y;
}

int intre(int x, int y, int x2, int y2){
    int x1=ox,y1=oy;

    if(x1>x2)
        swap(x1,x2);
    if(y1>y2)
        swap(y1,y2);

    if(x>=x1 && x<=x2 && y>=y1 && y<=y2)
        return 1;
    return 0;
}

int main()
{
    f>>n>>ox>>oy;
    nrd=n;

    for(i=1;i<=n;++i)
        f>>v[i].x>>v[i].y;

    sort(v+1,v+n+1,cond);

    for(i=n;i>0;--i){
        if(!v[i].fol){
            for(j=i-1;j>0;--j){
                if(!v[j].fol && intre(v[j].x,v[j].y,v[i].x,v[i].y)){
                    --nrd;
                    v[j].fol=1;
                }
            }
        }
    }

    g<<nrd;

    return 0;
}