#include <iostream>
#include <fstream>
#include <algorithm>

using namespace std;

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

int n, l1, l2, x[50005], y[50005], sol;

int main() {
    f >> n >> l1 >> l2;
    for (int i=1; i<=n; ++i) f>>x[i]>>y[i];
    sort(x+1,x+n+1);
    sort(y+1,y+n+1);
    for (int i=0; i<n; ++i)
    {
        sol+=max(x[1+i]-x[n-i]-l1,0);
        sol+=max(y[i+1]-y[n-i]-l2,0);
    }
    g << sol;
    return 0;
}