#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;

const int N = 5e4;

int distanta(vector <int> &v, int n, int lat)
{
    sort(v.begin(), v.end());
    int st = 0, dr = n - 1, sum = 0;
    while (v[dr] - v[st] > lat)
    {
        sum += v[dr--] - v[st++] - lat;
    }
    return sum;
}

int main()
{
    ifstream in("tribute.in");
    ofstream out("tribute.out");
    int n, lx, ly;
    in >> n >> lx >> ly;
    vector <int> x(n), y(n);
    for (int i = 0; i < n; i++)
    {
        in >> x[i] >> y[i];
    }
    in.close();
    out << distanta(x, n, lx) + distanta(y, n, ly);
    out.close();
    return 0;
}