#include <iostream>
#include <algorithm>
#include <fstream>
using namespace std;
ifstream fin("tribute.in");
ofstream fout("tribute.out");

int v[50001],c[50001],i;

int main()
{
    int n,x,y;
    fin >> n >> x >> y;
    for(i=1;i<=n;i++)
    {
        fin >> v[i] >> c[i];
    }
    sort(v+1,v+n+1);
    sort(c+1,c+n+1);
    int sum=0;
    for(i=1;i<=n/2;++i)
    {
        sum+=max(v[n-i+1]-v[i]-x,0);
        sum+=max(c[n-i+1]-c[i]-y,0);
    }
    fout << sum;
    return 0;
}