#include <iostream>#include <cstdio>#include <cstring>#include <cstdlib>#include <cmath>#include <algorithm>#include <string>#include <vector>#include <queue>#define Mod 1000000007#define eps 1e-8using namespace std;#define N 100017struct Point{    double x,y;    Point(double x=0, double y=0):x(x),y(y) {}    void input() { scanf("%lf%lf",&x,&y); }};typedef Point Vector;    bool operator < (const Line &L)const { return ang < L.ang; }};int dcmp(double x) {    if(x < -eps) return -1;    if(x > eps) return 1;    return 0;}template <class T> T sqr(T x) { return x * x;}Vector operator + (Vector A, Vector B) { return Vector(A.x + B.x, A.y + B.y); }Vector operator - (Vector A, Vector B) { return Vector(A.x - B.x, A.y - B.y); }Vector operator * (Vector A, double p) { return Vector(A.x*p, A.y*p); }Vector operator / (Vector A, double p) { return Vector(A.x/p, A.y/p); }bool operator < (const Point& a, const Point& b) { return a.x < b.x || (a.x == b.x && a.y < b.y); }bool operator >= (const Point& a, const Point& b) { return a.x >= b.x && a.y >= b.y; }bool operator <= (const Point& a, const Point& b) { return a.x <= b.x && a.y <= b.y; }bool operator == (const Point& a, const Point& b) { return dcmp(a.x-b.x) == 0 && dcmp(a.y-b.y) == 0; }double Dot(Vector A, Vector B) { return A.x*B.x + A.y*B.y; }double Length(Vector A) { return sqrt(Dot(A, A)); }double Angle(Vector A, Vector B) { return acos(Dot(A, B) / Length(A) / Length(B)); }double Cross(Vector A, Vector B) { return A.x*B.y - A.y*B.x; }Vector VectorUnit(Vector x){ return x / Length(x);}Vector Normal(Vector x) { return Point(-x.y, x.x) / Length(x);}double angle(Vector v) { return atan2(v.y, v.x); }double DisP(Point A,Point B){    return Length(B-A);}bool SegmentIntersection(Point A,Point B,Point C,Point D) {    if(dcmp(Cross(C-A,B-A)*Cross(D-A,B-A)) < 0 && dcmp(Cross(A-C,D-C)*Cross(B-C,D-C)) < 0) return true;    return false;}//data segmentstruct node{    Point P[2];}line[206];Point p[206];vector<pair<int,double> > G[206];double dis[206];int vis[206],tot,Ltot,S,E;//data endsvoid SPFA(){    for(int i=1;i<=tot;i++) dis[i] = Mod;    memset(vis,0,sizeof(vis));    queue<int> q;    q.push(S);    vis[S] = 1, dis[S] = 0;    while(!q.empty())    {        int u = q.front();        q.pop();        vis[u] = 0;        for(int i=0;i<G[u].size();i++)        {            int v = G[u][i].first;            double w = G[u][i].second;            if(dis[v] > dis[u] + w)            {                dis[v] = dis[u] + w;                if(!vis[v]) { q.push(v), vis[v] = 1; }            }        }    }}int main(){    int n,i,j,k,h;    double x,a,b,c,d;    while(scanf("%d",&n)!=EOF && n!=-1)    {        tot = 1,Ltot = 0;        p[1] = Point(0,5);        for(i=1;i<=n;i++)        {            scanf("%lf%lf%lf%lf%lf",&x,&a,&b,&c,&d);            p[++tot] = Point(x,a);            p[++tot] = Point(x,b);            p[++tot] = Point(x,c);            p[++tot] = Point(x,d);            line[++Ltot].P[0] = Point(x,0), line[Ltot].P[1] = Point(x,a);            line[++Ltot].P[0] = Point(x,b), line[Ltot].P[1] = Point(x,c);            line[++Ltot].P[0] = Point(x,d), line[Ltot].P[1] = Point(x,10);        }        p[++tot] = Point(10,5);        Point A,B;        for(i=0;i<=tot;i++) G[i].clear();        for(i=1;i<=tot;i++)        //start        {            for(j=i+1;j<=tot;j++)  //end            {                A = p[i], B = p[j];                for(k=1;k<=Ltot;k++)                {                    if(SegmentIntersection(A,B,line[k].P[0],line[k].P[1]))                        break;                }                if(k == Ltot+1)                {                    G[i].push_back(make_pair(j,DisP(A,B)));                    G[j].push_back(make_pair(i,DisP(A,B)));                }            }        }        S = 1, E = tot;        SPFA();        printf("%.2f\n",dis[E]);    }    return 0;}