#include <bits/stdc++.h>

#define REP(i, n) for(int i = 0 ; i < (int)n; ++i)

#define X first
#define Y second

using namespace std;

typedef pair<int, int> ii;

int solve(vector<ii> pnts, set<ii> & allpnts, bool swap){
	int mx = 0;

	sort(pnts.begin(), pnts.end());

	/*cerr << endl << endl << "SOLVE" << endl;

	for(auto && p : pnts){
		cerr << p.X << " " << p.Y << endl;
	}*/

	int lstX = -1;
	vector<int> lst;

	for(auto && p : pnts){
		if(p.X == lstX) lst.push_back(p.Y);
		else{
			REP(i, lst.size())for(int j = i+1; j < (int)lst.size(); ++j) if(lst[j]-lst[i] > mx){
				int d = lst[j]-lst[i];
				assert(d >= 0);
				
				REP(afkjgd, 2){
					ii p1, p2;
					if(!swap){
						p1 = {lstX+d, lst[i]};
						p2 = {lstX+d, lst[j]};
					} else{
						p1 = {lst[i], lstX+d};
						p2 = {lst[j], lstX+d};
					}

					if(allpnts.find(p1) != allpnts.end() && allpnts.find(p2) != allpnts.end())
						mx = abs(d);
					
					d*=-1;
				}
			}

			lst.clear();
			lstX = p.X;
			lst.push_back(p.Y);
		}
	}
	
	return mx;
}

bool testcase(){
	int n;

	if(!(cin >> n))return false;

	int sqn = 1;
	for(;sqn*sqn<n; ++sqn);

	vector<ii> pnts, pntsX, pntsY;

	set<ii> allpnts;

	int x, y;
	REP(i, n){
		cin >> x >> y;
		pnts.push_back({x, y});
		allpnts.insert({x, y});
	}

	sort(pnts.begin(), pnts.end());

	/*
	for(auto && p : pnts){
		cerr << p.X << " " << p.Y << endl;
	}*/

	int lstX = -1;
	vector<int> lstY;

	REP(i, n){
		auto p = pnts[i];
		if(p.X == lstX) lstY.push_back(p.Y);
		else{
			if((int)lstY.size() <= sqn){
				for(auto && y : lstY) pntsX.push_back(ii(lstX, y));
			} else{
				for(auto && y : lstY) pntsY.push_back(ii(y, lstX));
			}

			lstY.clear();

			lstX = p.X;
			lstY.push_back(p.Y);
		}
	}
	if((int)lstY.size() <= sqn){
		for(auto && y : lstY) pntsX.push_back(ii(lstX, y));
	} else{
		for(auto && y : lstY) pntsY.push_back(ii(y, lstX));
	}

	int ret =  max(solve(pntsX, allpnts, false), solve(pntsY, allpnts, true));
	
	cout << ret << endl;

	return true;
}


int main(){
	while(testcase());
	return 0;
}