#include <bits/stdc++.h>

using namespace std;

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

int n,dx,dy,i,x[50005],y[50005];

int sumobi(int v[], int n, int l)
{
    int sum=0,st=0,dr=n-1;
    sort(v,v+n);
    while ( st<dr && v[dr]-v[st]>l )
    {
        sum+=v[dr]-v[st]-l;
        st++;
        dr--;
    }
    return sum;
}

int main()
{
    f >> n >> dx >> dy;
    for(i = 0; i < n; i++)
        f >> x[i] >> y[i];
    g << sumobi(x,n,dx)+sumobi(y,n, dy);
    return 0;
}