#include <bits/stdc++.h>

using namespace std;

ifstream fin("tribute.in");
ofstream fout("tribute.out");
int n, lx, ly, i, s;
int x[50002], y[50002];

int main() {
    fin >> n >> lx >> ly;
    for(i = 1; i <= n; i++) fin >> x[i] >> y[i];
    sort(x + 1, x + n + 1);
    sort(y + 1, y + n + 1);
    for(i = 1; i <= n; i++) {
        if(x[n - i + 1] - x[i] <= lx) break;
        s += x[n - i + 1] - x[i] - lx;
    }
    for(i = 1; i <= n; i++) {
        if(y[n - i + 1] - y[i] <= ly) break;
        s += y[n - i + 1] - y[i] - ly;
    }
    fout << s;

    return 0;
}