#include <cstdio>
#include <algorithm>
#include <climits>

#define Nmax 50010

using namespace std;

int n , i , j , a , b , Dx , Dy , Lx , Ly , nrX_st , nrX_dr , nrY_jos , nrY_sus , costX = INT_MAX , costY = INT_MAX;
int X[Nmax] , Y[Nmax] , stX[Nmax] , drX[Nmax] , josY[Nmax] , susY[Nmax];

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

    for (scanf("%d %d %d", &n, &Dx, &Dy) , i = 1; i <= n; ++i)
    {
        scanf("%d %d", &a, &b);

        X[a]++; Y[b]++;
    }

    ///sume partiale pe vectorii de aparitie

    for (i = 0 , j = Nmax; i <= Nmax; ++i , --j)
    {
        stX[i] = stX[i-1] + nrX_st;

        josY[i] = josY[i-1] + nrY_jos;

        drX[j] = drX[j+1] + nrX_dr;

        susY[j] = susY[j+1] + nrY_sus;

         nrX_st += X[i] , nrY_jos += Y[i] , nrX_dr += X[j] , nrY_sus += Y[j];
    }

    ///line sweep pe Ox

    for (Lx = 0; Lx <= Nmax - Dx; ++Lx)
        costX = min(costX , stX[Lx] + drX[Lx+Dx]);

    ///line sweep pe Oy

    for (Ly = 0; Ly <= Nmax - Dy; ++Ly)
        costY = min(costY , josY[Ly] + susY[Ly+Dy]);


    printf("%d\n", costX + costY);

    return 0;
}