#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf32 1000000001
#define Inf64 2000000000000000005



int main(){
	
	int n;
	cin>>n;
	
	vector<long long> x(n),y(n),t(n);
	rep(i,n){
		cin>>x[i]>>y[i]>>t[i];
		/*
		x[i] = 100;
		y[i] = i;
		t[i] = i+1;
		*/
	}
	
	vector d(n,vector<long long>(n,Inf64));
	rep(i,n)d[i][i] = 0;
	
	rep(i,n){
		rep(j,n){
			if(i==j)continue;
			if(t[i]==t[j]){
				d[i][j] = (x[i]-x[j])*(x[i]-x[j]) + (y[i]-y[j])*(y[i]-y[j]);
			}
			else{
				long long X = x[i]*x[i] + y[i]*y[i];
				long long Y = x[j]*x[j] + y[j]*y[j];
				
				d[i][j] = ceill(powl(abs(sqrtl(X)-sqrtl(Y)),2.0));//abs(X-Y)*abs(X-Y);
				//cout<<i<<','<<j<<','<<d[i][j]<<endl;
			}
		}
	}
	
	rep(i,n){
		rep(j,n){
			rep(k,n){
				d[j][k] = min(d[j][k],max(d[j][i],d[i][k]));
			}
		}
	}
	
	cout<<d[0][n-1]<<endl;
	
    return 0;
}