#include<bits/stdc++.h>
using namespace std;
struct point{
	double x,y,z;
};
point *p;
bool cmp(point a,point b)
{
	if(a.z<b.z)
		return true;
}
double dis(point a,point b)
{
	return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y)+(a.z-b.z)*(a.z-b.z));
}
int main()
{
	int n;
	double ans=0;
	cin>>n;
	p=new point[n];
	for(int i=0;i<n;i++)
		cin>>p[i].x>>p[i].y>>p[i].z;
	sort(p,p+n,cmp);
	for(int i=0;i<n;i++)
		cout<<p[i].x<<" "<<p[i].y<<" "<<p[i].z<<endl;
	for(int i=0;i<n-1;i++)
		ans=ans+dis(p[i+1],p[i]);
	cout<<ans<<endl;
	return 0;
}