#include <bits/stdc++.h>
#define oo 50000
using namespace std;
ifstream f("tribute.in");
ofstream g("tribute.out");
typedef unsigned long long int ll;
ll n, dx, dy, x, y, xmax, ymax, xmin = 2e12, ymin = 2e12;
ll dsx[oo + 1], ddx[oo + 1], djy[oo + 1], dsy[oo + 1], fx[oo + 1], fy[oo + 1];

void Read()
{
    f>>n>>dx>>dy;
    for(int i = 1;i <= n;++i)
    {
        f>>x>>y;
        fx[x]++;
        fy[y]++;
    }
}

void Solve()
{
    ll sumx, sumy;
    sumx = fx[0];
    sumy = fy[0];
    for(int i = 1;i <= oo;++i)
    {
        dsx[i] = dsx[i - 1] + sumx;
        sumx += fx[i];

        djy[i] = djy[i - 1] + sumy;
        sumy += fy[i];
    }
    sumx = fx[oo];
    sumy = fy[oo];
    for(int i = oo - 1;i >= 0;--i)
    {
        ddx[i] = ddx[i + 1] + sumx;
        sumx += fx[i];

        dsy[i] = dsy[i + 1] + sumy;
        sumy += fy[i];
    }
    for(int i = 0;i <= oo - dx;++i)
        {
            xmin = min(xmin, dsx[i] + ddx[i + dx]);
            ymin = min(ymin, djy[i] + dsy[i + dy]);
        }
    g<<xmin + ymin<<'\n';
    g.close();
}

int main()
{
    Read();
    Solve();
    return 0;
}