#include <fstream>
#include <algorithm>
#include <iostream>
using namespace std;
ifstream in ("tribute.in");
ofstream out ("tribute.out");
int main()
{
    int n,dx,dy;
    in>>n>>dx>>dy;
    int v1[n],v2[n];
    for(int i=0; i<n; i++)
    {
        in>>v1[i]>>v2[i];
    }
    sort(v1,v1+n);
    sort(v2,v2+n);
    int r=0;
    for(int i=0; i<n/2; i++)
    {
        if (v1[n-i-1]-v1[i]-dx>0)
        {
            r+=v1[n-i-1]-v1[i]-dx;
        }
        if (v2[n-i-1]-v2[i]-dy>0)
        {
            r+=v2[n-i-1]-v2[i]-dy;
        }
    }
    out<<r;
    return 0;
}