#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
constexpr double eps = 1e-7;
constexpr double PI = acos(-1);
constexpr double inf = 1e9;
struct Point { double x, y; };        // 点
using Vec = Point;                    // 向量
struct Line { Point P; Vec v; };      // 直线（点向式），射线时为A->B
struct Seg { Point A, B; };           // 线段（存两个端点）
struct Circle { Point O; double r; }; // 圆（存圆心和半径）
using Points = std::vector<Point>;
using ConvexHull = std::vector<Point>;
const Point O = {0, 0};                        // 原点
const Line Ox = {O, {1, 0}}, Oy = {O, {0, 1}}; // 坐标轴

bool eq(double a, double b) { return abs(a - b) < eps; } // ==
bool gt(double a, double b) { return a - b > eps; }      // >
bool lt(double a, double b) { return a - b < -eps; }     // <
bool ge(double a, double b) { return a - b > -eps; }     // >=
bool le(double a, double b) { return a - b < eps; }      // <=
Vec operator + (const Vec &a,const Vec &b){return (Vec){a.x + b.x,a.y + b.y};}
Vec operator - (const Vec &a,const Vec &b){return (Vec){a.x - b.x,a.y - b.y};}
Vec operator * (const Vec &a,const double &b){return (Vec){b * a.x,b * a.y};}
Vec operator * (const double &a,const Vec &b){return (Vec){a * b.x,a * b.y};}
Vec operator / (const Vec &a,const double &b){return (Vec){a.x / b,a.y / b};}
double operator * (const Point &a,const Point &b){return a.x * b.x + a.y * b.y;}// dot // 点乘
double operator ^ (const Point &a,const Point &b){return a.x * b.y - a.y * b.x;}// cross  // 叉乘
bool operator < (const Point& a, const Point& b) {return a.x < b.x || (a.x == b.x && a.y < b.y);}
double len(Vec a){return sqrt(a * a);}

ll cross(Point a,Point b){return (ll)a.x * (ll)b.y - (ll)a.y * (ll)b.x;}
ll dot(Point a,Point b){return (ll)a.x * (ll)b.x + (ll)a.y * (ll)b.y;}

// Graham扫描法

// DEPENDS eq, lt, cross, V-V, P<P

// double theta(Point p) { return p == O ? -1 / 0. : atan2(p.y, p.x); } // 求极角
// void psort(Points &ps, Point c = O) {                                 // 极角排序
//     sort(ps.begin(), ps.end(), [&](auto a, auto b) {
//         return lt(theta(a - c), theta(b - c));
//     });
// }
/*
//极角排序
int qua(const Point &P){
  if(P.x == 0 && P.y == 0) return 0;
  if(P.x >= 0 && P.y >= 0) return 1;
  if(P.x < 0&& P.y >= 0) return 2;
  if(P.x<0 && P.y < 0) return 3;
  if(P.x >= 0 && P.y < 0) return 4;
  exit(-1); 
}
void psort(Points &ps, Point c = O){                               // 极角排序
    stable_sort(ps.begin(), ps.end(), [&](auto p1, auto p2) {
        return qua(p1 - c) < qua(p2 - c) || qua(p1 - c) == qua(p2 - c) && gt((Point)(p1 - c) ^ (Point)(p2 - c), 0);
    });
}
// 检查向量夹角acb小于180
bool check1(Point a,Point b,Point c){// 
    ll d = (a - c) ^ (b - c);
    if(d > 0)return true;
    if(d < 0)return false;
    return (a - c) * (b - c) > 0;
}

*/


bool check(Point p, Point q, Point r){ // 检查三个点组成的两个向量的旋转方向是否为逆时针
    return lt(0, (q - p) ^ (r - q));
}
ConvexHull Andrew(Points &ps){
    if(ps.size() == 1){
        return ps;
    }
    sort(ps.begin(), ps.end());
    std::vector<int> I{0}, used(ps.size());
    for (int i = 1; i < ps.size(); i++){
        //std::cout << ps[i].x << " " <<ps[i].y <<"\n";  
        while (I.size() > 1 && !check(ps[I[I.size() - 2]], ps[I.back()], ps[i]))
            used[I.back()] = 0, I.pop_back();
        used[i] = 1, I.push_back(i);
    }
    int tmp = I.size();
    for (int i = ps.size() - 2; i >= 0; i--){
        if (used[i])
            continue;
        while (I.size() > tmp && !check(ps[I[I.size() - 2]], ps[I.back()], ps[i]))
            used[I.back()] = 0, I.pop_back();
        used[i] = 1, I.push_back(i);
    }
    Points H;
    for (int i = 0; i < I.size() - 1; i++)
        H.push_back(ps[I[i]]);
    return H;
}//逆时针
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin >> n;
    vector<array<Point,3>> a(n);
    for(int i = 0;i < n;i ++) {
        for(int j = 0;j < 3;j ++) {
            cin >> a[i][j].x >> a[i][j].y;
        }
    }
    int N = (1 << n);
    vector<double> f(N),dp(N,1e9);
    auto calc = [&](Points &a) -> double{
        double ans = 0;
        int n = a.size();
        for(int i = 0;i < n;i ++) {
            ans += len(a[(i + 1) % n] - a[i]);
        }
        return ans;
    };
    for(int i = 1;i < N;i ++) {
        vector<Point> b;
        for(int j = 0;j < n;j ++) {
            if(i & (1 << j)) {
                for(int k = 0;k < 3;k ++) b.push_back(a[j][k]);
            }
        }
        auto C = Andrew(b);
        f[i] = calc(C);
        // cerr << fixed << setprecision(10) << f[i] << "\n";
    }
    dp[0] = 0;
    for(int s = 1;s < N;s ++) {
        for(int i = s; i; i = (i - 1) & s) {
            dp[s] = min(dp[s],dp[i ^ s] + f[i]);
        }
    }
    cout << fixed << setprecision(10) << dp[N - 1] << endl;
}