#include <iostream>

#include <stdio.h>

#include <string.h>

#include <algorithm>

#include <queue>

#include <map>

#include <vector>

#include <set>

#include <string>

#include <math.h>

#define LL long long

#define mem(i, j) memset(i, j, sizeof(i))

#define rep(i, j, k) for(int i = j; i <= k; i++)

#define dep(i, j, k) for(int i = k; i >= j; i--)

#define pb push_back

#define make make_pair

#define INF 1e20

#define inf LLONG_MAX

#define PI acos(-1)

using namespace std;

const int N = 1e2 + ;

const double eps = 1e-;

struct Point {

    double x, y;

    Point(double x = , double y = ) : x(x), y(y) { } /// 构造函数

};

/// 向量加减乘除

inline Point operator + (const Point& A, const Point& B) { return Point(A.x + B.x, A.y + B.y); }

inline Point operator - (const Point& A, const Point& B) { return Point(A.x - B.x, A.y - B.y); }

inline Point operator * (const Point& A, const double& p) { return Point(A.x * p, A.y * p); }

inline Point operator / (const Point& A, const double& p) { return Point(A.x / p, A.y / p); }

inline int dcmp(const double& x) { if(fabs(x) < eps) return ; else return x <  ? - : ; }

inline double Cross(const Point& A, const Point& B) { return A.x * B.y - A.y * B.x; } /// 叉积

inline double Dot(const Point& A, const Point& B) { return A.x * B.x + A.y * B.y; } /// 点积

inline double Length(const Point& A) { return sqrt(Dot(A, A)); } /// 向量长度

inline double Angle(const Point& A, const Point& B) { return acos(Dot(A, B) / Length(A) / Length(B)); } /// 向量A,B夹角

inline Point GetLineIntersection(const Point P, const Point v, const Point Q, const Point w) {///求直线p + v*t 和 Q + w*t 的交点，需确保有交点，v和w是方向向量

    Point u = P - Q;

    double t = Cross(w, u) / Cross(v, w);

    return P + v * t;

}

inline bool Onsegment(Point p, Point a1, Point a2) { /// 判断点p是否在线段p1p2上

    return dcmp(Cross(a1 - p, a2 - p)) ==  && dcmp(Dot(a1 - p, a2 - p)) <= ;

}

inline bool SegmentProperInsection(Point a1, Point a2, Point b1, Point b2) { /// 判断线段是否相交

    if(dcmp(Cross(a1 - a2, b1 - b2)) == ) /// 两线段平行

        return Onsegment(b1, a1, a2) || Onsegment(b2, a1, a2) || Onsegment(a1, b1, b2) || Onsegment(a2, b1, b2);

    Point tmp = GetLineIntersection(a1, a2 - a1, b1, b2 - b1);

    return Onsegment(tmp, a1, a2) && Onsegment(tmp, b1, b2);

}

Point P[N];

double dis[N][N];

int main() {

    int n;

    double x, y1, y2, y3, y4;

    while(scanf("%d", &n) && n != -) {

        int cnt = ;

        rep(i, , n) {

            scanf("%lf %lf %lf %lf %lf", &x, &y1, &y2, &y3, &y4);

            P[++cnt] = Point(x, y1);

            P[++cnt] = Point(x, y2);

            P[++cnt] = Point(x, y3);

            P[++cnt] = Point(x, y4);

        }

        rep(i, , cnt + ) rep(j, , cnt + ) if(i == j) dis[i][j] = ; else dis[i][j] = INF;

        rep(i, , cnt) { /// 判断(0,5)是否能直达P[i]，P[i]是否能直达(10,5)

            bool flag = ;

            int up = ((i + ) / ) *  + ;

            up -= ;

            for(int j = ; j < up; j += ) { /// (0,5)是否能直达P[i]

                if(SegmentProperInsection(P[j], P[j + ], Point(, ), P[i]) == false && SegmentProperInsection(P[j + ], P[j + ], Point(, ), P[i]) == false) flag = ;

            }

            if(!flag) dis[][i] = dis[i][] = Length(Point(, ) - P[i]);

            flag = ;

            for(int j = up + ; j <= cnt; j += ) { /// P[i] 是否能直达(10,5)

                if(SegmentProperInsection(P[j], P[j + ], Point(, ), P[i]) == false && SegmentProperInsection(P[j + ], P[j + ], Point(, ), P[i]) == false) flag = ;

            }

            if(!flag) dis[cnt + ][i] = dis[i][cnt + ] = Length(Point(, ) - P[i]);

        }

        rep(i, , cnt) rep(j, i + , cnt) { /// 枚举两点，判断这两点是否能直达

            int st = ((i + ) / ) *  + ;

            int ed = ((j + ) / ) * ;

            bool flag = ;

            for(int k = st; k <= ed; k += ) {

                if(SegmentProperInsection(P[k], P[k + ], P[i], P[j]) == false && SegmentProperInsection(P[k + ], P[k + ], P[i], P[j]) == false) flag = ;

            }

            if(!flag) dis[i][j] = dis[j][i] = Length(P[i] - P[j]);

        }

        bool flag = ;

        for(int i = ; i <= cnt; i += ) /// 判断(0,5)是否能直达(10,5)

            if(SegmentProperInsection(P[i], P[i + ], Point(, ), Point(, )) == false && SegmentProperInsection(P[i + ], P[i + ], Point(, ), Point(, )) == false) flag = ;

        if(!flag) dis[][cnt + ] = dis[cnt + ][] = ;

        rep(k, , cnt + ) rep(i, , cnt + ) rep(j, , cnt + )

            if(dis[i][k] + dis[k][j] < dis[i][j]) dis[i][j] = dis[i][k] + dis[k][j];

        printf("%.2f\n", dis[][cnt + ]);

    }

    return ;

}