#include<iostream>
#include<fstream>
#include<cmath>
using namespace std;

int main()
{
	ifstream fin("ppg.in");
	ofstream fout("ppg.out");
	int n,f[100][100],x[100],y[100],i,j,k,t;
	fin>>n;
	for(i=1;i<=n;i++)
		for(j=1;j<=n;j++)
			f[i][j]=99999999;
	for(i=1;i<=n;i++)
		fin>>x[i]>>y[i];
	for(i=1;i<=n;i++)
		for(j=1;j<=n;j++)
		{
			t=(abs(x[i]-x[j])+abs(y[i]-y[j]));
			if(t%2==0)
				t/=2;
			else
				t=t/2+1;
			f[i][j]=t;
		}
	for(i=1;i<=n;i++)
		for(j=1;j<=n;j++)
			for(k=1;k<=n;k++)
				if(f[i][j]>f[i][k]+f[k][j])
					f[i][j]=f[i][k]+f[k][j];
    int maxn=0;
	for(i=1;i<=n;i++)
		for(j=1;j<=n;j++)
			if(f[i][j]>maxn)
				maxn=f[i][j];
    fout<<maxn<<endl;
	return 0;
}