#include <cstdio>
#include <algorithm>

#define NMAX 50007

using namespace std;

int a[NMAX], b[NMAX], n, dx, dy;

int solve(int x[], int c){
    sort(x + 1, x + n + 1);
    int Ans = 0;
    for(int i = 1; i <= n / 2; ++i)
        Ans += max(x[n - i + 1] - x[i] - c, 0);
    return Ans;
}

int main(){
    freopen("tribute.in", "r", stdin);
    freopen("tribute.out", "w", stdout);
    scanf("%d %d %d", &n, &dx, &dy);
    for(int i = 1; i <= n; ++i)
        scanf("%d %d", &a[i], &b[i]);
    printf("%d\n", solve(a, dx) + solve(b, dy));
    return 0;
}