#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;

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

struct client
{
    int x,y;
}v[50001];

vector<client> v1,v2,v3,v4;

int n,s[50001],l,xi,yi;

bool cmp (client a, client b)
{
    return a.x < b.x;
}

void read ()
{
    fin>>n;

    fin>>xi>>yi;

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

        v[i].x -= xi;
        v[i].y -= yi;

        if (v[i].x > 0)
        {
            if (v[i].y > 0)
                v1.push_back (v[i]);
            else
            {
                v[i].y = -v[i].y;
                v2.push_back (v[i]);
            }
        }
        else
        {
            v[i].x = -v[i].x;

            if (v[i].y > 0)
                v3.push_back (v[i]);
            else
            {
                v[i].y = -v[i].y;
                v4.push_back (v[i]);
            }
        }
    }
}

int bs (int x)
{
    int lo = -1, hi = l+1;

    while (hi - lo > 1)
    {
        int mid = (lo + hi)/2;

        if (x < s[mid])
          lo = mid;
        else hi = mid;
    }

    return hi;
}

int solve (vector<client> v)
{
    sort (v.begin(),v.end(),cmp);

    l = 0;
    s[0] = 2000000001;

    for (int i=0; i<v.size(); ++i)
    {
        int pos = bs (v[i].y);

        if (pos == l+1)
            ++l;

        s[pos] = v[i].y;
    }

    return l;
}

int main()
{
    read ();

    fout<<solve(v1)+solve(v2)+solve(v3)+solve(v4);
}