#include <cassert>

#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>

// C++
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
//#include <boost/foreach.hpp>
//#include <boost/range/algorithm.hpp>
#define rep(i,j,k) for(int i=(int)j;i<(int)k;i++)
#define ll long long
#define Sort(v) sort(all(v))
#define INF 1000000000
#define END return 0
#define pb push_back
#define se second
#define fi first
#define pb push_back
#define all(v) (v).begin() , (v).end()
#define MP make_pair
#define MOD 1000000007LL;
using namespace std;
int day[12]={31,28,31,30,31,30,31,31,30,31,30,31};

int main (){ 
    int n;
    while(cin>>n && n){
        vector<pair<int,int>> v(n);
        rep(i,0,n)cin>>v[i].first>>v[i].second;
        Sort(v);
        int ans=0;
        rep(i,0,n-1){
            rep(j,i+1,n){
                int dx=v[i].first-v[j].first;
                int dy=v[i].second-v[j].second;
                //cout<<dx<<" "<<dy<<endl;
                //  printf("%d,%d\n",v[i].first-dy,v[i].second+dx);
                //  printf("%d,%d\n",v[j].first-dy,v[j].second+dx);
                //cout<<binary_search(all(v),pair<int,int>(v[i].first-dy,v[i].second+dx))<<endl;
                //cout<<binary_search(all(v),pair<int,int>(v[i].first+dy,v[i].second-dx))&&binary_search(all(v),pair<int,int>(v[j].first+dy,v[j].second-dx))<<" "<<binary_search(all(v),pair<int,int>(v[i].first-dy,v[i].second+dx))&&binary_search(all(v),pair<int,int>(v[j].first-dy,v[j].second+dx))<<endl;
                if(binary_search(all(v),pair<int,int>(v[i].first+dy,v[i].second-dx))&&binary_search(all(v),pair<int,int>(v[j].first+dy,v[j].second-dx)))ans=max(ans,dx*dx+dy*dy);
                if(binary_search(all(v),pair<int,int>(v[i].first-dy,v[i].second+dx))&&binary_search(all(v),pair<int,int>(v[j].first-dy,v[j].second+dx)))ans=max(ans,dx*dx+dy*dy);
                
            }
        }
        cout<<ans<<endl;
    }

    return 0;
}


/*
10
9 4
4 3
1 1
4 2
2 4
5 8
4 0
5 3
0 5
5 2
0

*/



Measured memory_bytes: 3052