#include <fstream>
#include <iostream>
using namespace std;
int main()
{
	int n,x,y,i,j,k,z,t,qx,qy,s=0;
	ifstream inFile("tribute.in");
	inFile >> n >> x >> y;
	for (i=0; i<n; i++)
	{
		inFile >> z >> t;
		qx=0; qy=0;
		for (j=0; j<=x; j++)
		{
			if (j==z)
				qx=1;
			for (k=0; k<=y; k++)
				if (k==t)
					qy=1;
		}
		if (qx!=1 && qy!=1)
			s=s+(z-x)+(t-y);
		if (qx==1 && qy!=1)
			s+=(t-y);
		if (qx!=1 && qy==1)
			s+=(z-x);
	}
	inFile.close();
	ofstream outFile("tribute.out");
	outFile << s << "\n";
	outFile.close();
	return 0;
}