#include <fstream>
#include <algorithm>
using namespace std;
ifstream f("pachete.in");
ofstream g("pachete.out");
int n,xs,ys,nr[6];
struct pct
{
    int x,y;
}cadran[4][50005];
bool comp(pct X,pct Y)
{
    if(X.x==Y.x)
        return X.y<Y.y;
    return X.x<Y.x;
}
int sol[50005];
int solve_cadran(int k)
{
    if(nr[k]==0)
        return 0;
    int nr1=0;
    sol[++nr1]=cadran[k][1].y;

    for(int i=2;i<=nr[k];i++)
    {
        int st=1;
        int dr=nr1;
        int val=cadran[k][i].y;
        while(st<=dr)
        {
            int mj=(st+dr)/2;
            if(sol[mj]>val)
                st=mj+1;
            else
                dr=mj-1;
        }
        if(st>nr1)
            nr1++;
        sol[nr1]=val;
    }
    return nr1;
}
int main()
{
    f>>n>>xs>>ys;
    for(int i=1;i<=n;i++)
    {
        int X,Y;
        f>>X>>Y;
        X-=xs;
        Y-=ys;
        if(X>=0&&Y>=0)
        {
            nr[1]++;
            cadran[1][nr[1]]={X,Y};
        }
        else
        if(X>=0)
        {
            nr[2]++;
            cadran[2][nr[2]]={X,-Y};
        }
        else
        if(X<0&&Y<0)
        {
            nr[3]++;
            cadran[3][nr[3]]={-X,-Y};
        }
        else
        {
            nr[4]++;
            cadran[4][nr[4]]={-X,Y};
        }
    }
    //g<<nr[1]<<" "<<nr[2];
    sort(cadran[1]+1,cadran[1]+nr[1]+1,comp);
    sort(cadran[2]+1,cadran[2]+nr[2]+1,comp);
    sort(cadran[3]+1,cadran[3]+nr[3]+1,comp);
    sort(cadran[4]+1,cadran[4]+nr[4]+1,comp);
    int ans=0;
    for(int k=1;k<=4;k++)
        ans+=solve_cadran(k);
    g<<ans;
    return 0;
}