#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;

int n, s;
int x, y, xf, yf;
vector <int> drum;

struct cadran{
    int x, y;
};
vector <cadran> c[5];

bool sortare (cadran a, cadran b)
{
    return a.x < b.x;
}

void trans (int p)
{
    for (int i=0; i<c[p].size(); i++){
        int pp = 0;
        for (int j=0; j<drum.size() && pp == 0; j++){
            if (c[p][i].y >= drum[j]){
                pp = 1;
                drum [j] = c[p][i].y;
            }
        }

        if (pp == 0){
            drum.push_back (c[p][i].y);
        }
    }

    s += drum.size();
    drum.clear();
}

int main ()
{
    freopen ("pachete.in", "r", stdin);
    freopen ("pachete.out", "w", stdout);

    scanf ("%d %d %d", &n, &xf, &yf);

    for (int i=1; i<=n; i++){
        scanf ("%d %d", &x, &y);
        if (x >= xf){
            if (y >= yf){
                c[1].push_back ({x,y});
            }
            else{
                y = yf - y + yf;
                c[2].push_back ({x,y});
            }
        }
        else{
            if (y >= yf){
                x = xf - x + xf;
                c[3].push_back ({x,y});
            }
            else{
                x = xf - x + xf;
                y = yf - y + yf;
                c[4].push_back ({x,y});
            }
        }
    }

    for (int i=1; i<=4; i++){
        sort (c[i].begin(), c[i].end(), sortare);
        trans (i);
    }

    printf ("%d", s);

    return 0;
}