#include <fstream>
#include <algorithm>

using namespace std;

ifstream fin ("pachete.in");
ofstream fout ("pachete.out");

int di[]={-1,-1,1,1};
int dj[]={1,-1,1,-1};
int n,xi,yi,k,sol,rez,D,i,p,u,mij,d[50005];
struct data1{
    int x;
    int y;
}v[50005];
struct data2{
    int x;
    int y;
}cadran[50005];

int cmp (data2 a, data2 b) {
    if (a.x!=b.x)
        return a.x<b.x;
    else
        return a.y<b.y;
}

int main () {

    fin>>n>>xi>>yi;
    for (i=1;i<=n;i++) {
        fin>>v[i].x>>v[i].y;
        v[i].x-=xi;
        v[i].y-=yi;
    }
    for (D=0;D<=3;D++) {
        k=0;sol=0;
        for (i=1;i<=n;i++) {
            if (v[i].x*di[D]>=0 && v[i].y*dj[D]>=0) {
                cadran[++k].x=v[i].x*di[D];
                cadran[k].y=v[i].y*dj[D];
            }
        }
        sort (cadran+1,cadran+k+1,cmp);
        if (k!=0){
            d[0]=-1;
            d[++sol]=1;
        }
        for (i=2;i<=k;i++) {

            p=1;u=sol;
            while (p<=u) {
                mij=(p+u)/2;
                if (cadran[d[mij]].y>=cadran[i].y)
                    p=mij+1;
                else
                    u=mij-1;
            }
            d[p]=i;
            if (p>sol)
                sol++;

        }
        rez+=sol;
    }
    fout<<rez<<"\n";

    return 0;
}