#include <fstream>
#include <algorithm>

using namespace std;

int x[5001], y[5001];

int main() {
  ifstream cin ("tribute.in");
  ofstream cout ("tribute.out");
  int n, dx, dy, i, sol;
  cin >> n >> dx >> dy;
  for (i = 1; i <= n; i++)
    cin >> x[i] >> y[i];
  sort(x + 1, x + n + 1);
  sort(y + 1, y + n + 1);
  sol = 0;
  for (i = 1; i <= n; i++) {
    if (x[i + 1] - x[n - i] - dx > 0)
      sol += x[i + 1] - x[n - i] - dx;
    if (y[i + 1] - y[n - i] - dy > 0)
      sol += y[i + 1] - y[n - i] - dy;
  }
  cout << sol;
  return 0;
}