#include <bits/stdc++.h>
#define ll long long
#define NMAX 50001

using namespace std;

ifstream fin("tribute.in");
ofstream fout("tribute.out");

int x[NMAX], y[NMAX];

int main() {
    int n, dx, dy;
    fin >> n >> dx >> dy;
    for(int i = 1; i <= n; i++)
        fin >> x[i] >> y[i];
    sort(x + 1, x + n + 1);
    sort(y + 1, y + n + 1);

    int ans = 0;
    for(int i = 1; i <= n; i++) {
        ans += max(0, x[i + 1] - x[n - i] - dx);
        ans += max(0, y[i + 1] - y[n - i] - dy);
    }

    fout << ans;
    return 0;
}