#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;
	
}