#include <fstream>
#include <algorithm>

using namespace std;

const int Nmax = 50000;
int x[Nmax], y[Nmax];

int main()
{
    ifstream fin("tribute.in");
    ofstream fout("tribute.out");
    int dy, dx, n;
    fin >> n >> dx >> dy;
    for (int i = 0; i < n; i++)
    {
        fin >> x[i] >> y[i];
    }
    sort(x, x + n);
    sort(y, y + n);
    int i = 0, j = n - 1;
    long long ans = 0;
    while (i < j)
    {
        if (x[j] - x[i] > dx)
        {
            ans += x[j] - x[i] - dx;
        }
        i++;
        j--;
    }
    i = 0;
    j = n - 1;
    while (i < j)
    {
        if (y[j] - y[i] > dx)
        {
            ans += y[j] - y[i] - dx;
        }
        i++;
        j--;
    }
    fout << ans;
    return 0;
}