#include <cstdio>
#include <string.h>
#include <algorithm>

using namespace std;

#define Nmax 50005
#define x first
#define y second

int n, x0, y0, sol;
pair<int, int> punct[Nmax];
int s[Nmax], sir[Nmax];

void citire()
{
    int i;
    scanf("%d\n", &n);
    scanf("%d %d\n", &x0, &y0);
    for (i=1; i<=n; ++i)
    {
        scanf("%d %d\n", &punct[i].x, &punct[i].y);
        punct[i].x -= x0;
        punct[i].y -= y0;
    }
}

void solve2(int n)
{
    int i, st, dr, mij, l = 0, ind = 0;
    memset(sir, -1, sizeof(sir));
    for (i=1; i<=n; ++i)
    {
        st = 1;
        dr = l + 1;
        while (st <= dr)
        {
            mij = (st + dr) / 2;
            if (sir[mij] < s[i])
            {
                ind = mij;
                dr = mij - 1;
            }
            else
                st = mij + 1;
        }
        sir[ind] = s[i];
        if (ind > l)
            l = ind;
    }
    sol += l;
}

int cmpy(const pair<int, int> a, const pair<int, int> b)
{
    if (a.y <= b.y)
        if (a.y < b.y)
            return 1;
        else if (a.x > b.x)
            return 1;
    return 0;
}

void solve()
{
    int m, i;

    sort(punct+1, punct+n+1);    
    // cadran 1
    m = 0;
    for (i=1; i<=n; ++i)
        if (punct[i].x >= 0 && punct[i].y > 0)
            s[++m] = punct[i].y;
    solve2(m);
    
    // cadran 3
    m = 0;
    for (i=1; i<=n; ++i)
        if (punct[i].x <= 0 && punct[i].y < 0)
            s[++m] = -punct[i].y;
    reverse(s + 1, s + m + 1);
    solve2(m);
    
    // cadran 2
    m = 0;
    sort(punct+1, punct+n+1, cmpy);
    for (i=1; i<=n; ++i)
        if (punct[i].x < 0 && punct[i].y >= 0)
            s[++m] = -punct[i].x;
    solve2(m);
    
    // cadran 4
    m = 0;
    for (i=1; i<=n; ++i)
        if (punct[i].x > 0 && punct[i].y <= 0)
            s[++m] = punct[i].x;
    reverse(s + 1, s + m + 1);
    solve2(m);
    
    printf("%d\n", sol);
}

int main()
{
    freopen("pachete.in", "r", stdin);
    freopen("pachete.out", "w", stdout);
    citire();
    solve();
    return 0;
}