#include <bits/stdc++.h>
#define ll long long
#define mid (l+r>>1)
using namespace std;
const int N=105;
int n,m,k,s,t,pre[11],fa[N],tot;
struct node{
	int x,y;
	bool operator<(const node &k)const{
		return x<k.x;
	}
}a[N];
struct node1{
	int x,y;
	ll l;
	bool operator<(const node1 &k)const{
		return l<k.l;
	}
}e[N*11];
ll ans;
ll calc(int i,int j){
	return (ll)(a[i].x-a[j].x)*(a[i].x-a[j].x)+(ll)(a[i].y-a[j].y)*(a[i].y-a[j].y);
}
int getfa(int u){
	return fa[u]==u?u:fa[u]=getfa(fa[u]);
}
int main(){
	cin>>n;
	for (int i=1;i<=n;++i)
		cin>>a[i].x>>a[i].y;	
	sort(a+1,a+1+n);
	for (int i=1;i<=n;++i){
		for (int j=0;j<=10;++j)
			if (pre[j]) e[++tot]={pre[j],i,calc(pre[j],i)};
			pre[a[i].y]=i;
	}
	sort(e+1,e+1+tot);
	for (int i=1;i<=n;++i) fa[i]=i;
	for (int i=1;i<=tot;++i){
		s=getfa(e[i].x);
		t=getfa(e[i].y);
		if (s!=t) ans+=e[i].l,fa[s]=t;
	}
	cout<<ans;
}