#include <fstream>
#include <algorithm>

using namespace std;
ifstream in("tribute.in");
ofstream out("tribute.out");

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