#include <bits/stdc++.h>

using namespace std;
int ox[50005];
int oy[50005];
int main()
{
    freopen("tribute.in","r",stdin);
    freopen("tribute.out","w",stdout);
    int n,dx,dy,x,y;
    scanf("%d %d %d",&n,&dx,&dy);
    for(int i=1; i<=n; ++i)
    {
        scanf("%d %d",&x,&y);
        ox[i]=x;
        oy[i]=y;
    }
    sort(ox+1,ox+n+1);
    sort(oy+1,oy+n+1);
    int ans=0;
    for(int i = 1; i <= n; i++)
    {
        ans+=max(0,ox[i+1]-ox[n-i]-dx);
        ans+=max(0,oy[i+1]-oy[n-i]-dy);
    }
    printf("%d\n",ans);
    return 0;
}