#include <iostream>
#include <fstream>
#include <algorithm>
using namespace std;
ifstream fin("tribute.in");
ofstream fout("tribute.out");
int n,lungime,latime,x[50010],y[50010],d;
pair<int,int> coordonate[1000];
int main(){
    fin>>n>>lungime>>latime;
    for(int i=1;i<=n;i++){
        fin>>x[i]>>y[i];
       // fin>>coordonate[i].first>>coordonate[i].second;
      //  f[coordonate[i].second+1]=1;
   //     capatlatime=max(capatlatime,coordonate[i].second);
    }
   /* for(int i=1;i<=capatlatime+1;i++){
       // cout<<f[i]<<" "<<i<<endl;
        if(latime<i)
            dlung[1]+=(i-latime)*f[i];
        f[i]+=f[i-1];
       // cout<<f[i]<<" ";
    }cout<<dlung[1]<<endl;
    for(int i=2;i<=capatlatime;i++){
        dlung[i]=dlung[i-1]+((f[i-1]*(f[i-1]+1))/2)-(f[capatlatime]-i);
        cout<<dlung[i]<<" "<<((f[i-1]*(f[i-1]+1))/2)<<endl;

        */
        sort(x+1,x+1+n);
        sort(y+1,y+1+n);
        for(int i=1;i<=n/2;i++)
             d+=max(x[n-i+1]-x[i]-lungime,0)+max(y[n-i+1]-y[i]-latime,0);


    fout<<d;



    return 0;
}