#include <iostream>
#include <algorithm>
#include <fstream>
using namespace std;

ifstream in("tribute.in");
ofstream out("tribute.out");

int maxim(int a,int b)
{
    if(a>b)
        return a;
    return b;
}
int main()
{
    int n,x,y,a[50001],b[50001],i,S=0;
    in>>n>>x>>y;
    for(i=1;i<=n;i++)
        in>>a[i]>>b[i];
    sort(a+1,a+n+1);
    sort(b+1,b+n+1);
    for(i=1;i<=n/2;i++)
    {
        S=S+maxim(a[n-i+1]-a[i]-x,0);
        S=S+maxim(b[n-i+1]-b[i]-y,0);
    }
    out<<S;
    return 0;
}