#include<stdio.h>
#include <algorithm>
using namespace std;
FILE*f=fopen("tribute.in","r");
FILE*g=fopen("tribute.out","w");
int p,u,i,k,m,dx,dy,vx[50002],vy[50002],n;
int main() {
	fscanf(f,"%d%d%d",&n,&dx,&dy);
	dx++;
	dy++;
	for(i=1;i<=n;i++)
		fscanf(f,"%d%d",&vx[i],&vy[i]);
	
	sort(vx+1,vx+1+n);
	sort(vy+1,vy+1+n);
				
	p=1;
	u=n;
	while(p<=u){
		k=vx[u]-vx[p]+1-dx;
		if(k>0)
			m+=k;
		k=vy[u]-vy[p]+1-dy;
		if(k>0)
			m+=k;
		p++;
		u--;
		
	}

	fprintf(g,"%d",m);
	
	
	fclose(g);
	fclose(f);
	return 0;
}