#include <fstream>
#include <algorithm>
using namespace std;
int lin[500001], col[500001];
int rez(int v[], int n, int dx){
    int i, x1, x2, m, s=0;
    m=v[n/2];
    x1=v[(n-1)/2];
    x2=v[n/2]+1;
    for(i=0;i<n/2;i++){
        s+=((v[x1]-v[x2]-dx)>0)*(v[x1]-v[x2]-dx);
    }
    return s;
}
ifstream fin("tribute.in");
ofstream fout("tribute.out");

int main()
{
    int n, dx, dy, i, x, y, x1, x2, xd, xs;
    fin>>n>>dx>>dy;
    for(i=0;i<n;i++){
        fin>>lin[i]>>col[i];
    }
    sort(lin,lin+n);
    sort(col,col+n);
    fout<<rez(lin,n,dx)+rez(col,n,dy);
    return 0;
}