#include <bits/stdc++.h>
#define mp make_pair
#define REP(A,B) for(int (A)=0;(A)<(B);(A)++)
#define pb push_back
using namespace std;
long double objem[111111];
long double casy[111111];
long long pritok[111111];
int A[111111];
#define SQN 350
set<int> S;
int main()
{
	int n;
	while(scanf("%d", &n) == 1) {
		map<int, vector<int>> Rws, Cls;
		set< pair<int, int> > body;
		REP(i, n) {
			int x,y;
			scanf("%d%d", &x, &y);
			body.insert(mp(y,x));
			if(Rws.count(x) == 0) {
				Rws[x] = vector<int>();
			}
			Rws[x].pb(y);		
			if(Cls.count(y) == 0) {
				Cls[y] = vector<int>();
			}
			Cls[y].pb(x);
		}
		int ans = 0;
		vector<int> dlouhyR, dlouhyS;
		for(auto& x : Rws) {
			int rnum = x.first;
			if(x.second.size() < SQN) { 
				vector<int>& v = x.second;
				REP(i, v.size()) for(int j = i+1; j < v.size(); j++) {
					int D = abs(v[i]-v[j]);
					if((body.count(mp(v[i], rnum-D)) && body.count(mp(v[j], rnum-D)))
					  || body.count(mp(v[i], rnum+D)) && body.count(mp(v[j], rnum+D))) {
						ans = max(ans, D);
					}
				}
			} else dlouhyR.pb(rnum);
		}
		for(auto& x : Cls) {
			int colnum = x.first;
			if(x.second.size() < SQN) { 
				vector<int>& v = x.second;
				REP(i, v.size()) for(int j = i+1; j < v.size(); j++) {
					int D = abs(v[i]-v[j]);
					if((body.count(mp(colnum-D, v[i])) && body.count(mp(colnum-D, v[j])))
					  || body.count(mp(colnum+D, v[i])) && body.count(mp(colnum+D, v[j]))) {
						ans = max(ans, D);
					}
				}
			} else dlouhyS.pb(colnum);
		}
		for(int i = 0; i < dlouhyR.size(); i++)
			for(int j = i+1; j < dlouhyR.size(); j++) {
				for(int k = 0; k < dlouhyS.size(); k++) {
					int D = abs(dlouhyR[i]-dlouhyR[j]);
					int s = dlouhyS[k];
					int r1 = dlouhyR[i];
					int r2 = dlouhyR[j];
					if((
						body.count(mp(s, r1)) && body.count(mp(s, r2)) &&
						body.count(mp(s+D, r1)) && body.count(mp(s+D, r2))
						))
						ans = max(ans, D);
				}
			}

		printf("%d\n", ans);
	}
	return 0;
}