#include <fstream>
#include <vector>
#include <deque>
#include <algorithm>
#define x first
#define y second
using namespace std;

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

int n,x,y,i,j,k,sol,d[50001],cnt,st,dr,mid;
vector <pair<int,int> > v[5];

int cunt(int x){

    cnt=0;

    for(i=0;i<v[x].size();i++){
        st=1;
        dr=cnt;

        while(st<=dr){
            mid=(st+dr)/2;

            if(v[x][i].y>v[x][d[mid]].y)
                st=mid+1;
            else
                dr=mid-1;
        }

        if(st==cnt+1)
            cnt++;
        d[st]=i;
    }

    return cnt;
}

int main(){
    fin>>n>>x>>y;
    for(i=1;i<=n;i++){
        fin>>j>>k;
        j-=x;
        k-=y;

        if(j>=0){
            if(k>=0)
                v[1].push_back(make_pair(j,k));
            else
                v[4].push_back(make_pair(j,-k));
        }else{
            if(k>=0)
                v[2].push_back(make_pair(-j,k));
            else
                v[3].push_back(make_pair(-j,-k));
        }
    }

    sort(v[1].begin(),v[1].end());
    sol+=cunt(1);

    sort(v[2].begin(),v[2].end());
    sol+=cunt(2);

    sort(v[3].begin(),v[3].end());
    sol+=cunt(3);

    sort(v[4].begin(),v[4].end());
    sol+=cunt(4);

    fout<<sol;

    return 0;
}