#include  <iostream>

#include  <algorithm>

#include   <cstring>

#include   <cstdlib>

#include   <iomanip>

#include   <cassert>

#include    <bitset>

#include    <cctype>

#include    <cstdio>

#include    <string>

#include    <vector>

#include     <stack>

#include     <cmath>

#include     <queue>

#include      <list>

#include       <map>

#include       <set>

using namespace std;

const int maxn=;

const double eps=1e-;

int sgn(double x){ if(fabs(x) < eps) return ;  if(x >) return ; return -; }

int dcmp(double x, double y){ if(fabs(x - y) < eps) return ; if(x > y) return ;return -;}

struct Point  { double x,y; Point(double x,double y)      { x=x;y=y; };  Point() {};  };

struct Segment{ Point a,b;  Segment(Point x,Point y )     { a=x;b=y; };  Segment(){}; };

struct Line   { Point a,b;  Line(Point x,Point y )        { a=x;b=y; };  Line(){};    };

typedef Point Vector;

/*Vector operator + (Vector A, Vector B){ return Vector(A.x+B.x, A.y+B.y); } // 向量相加

Vector operator - (Point  A, Point  B){ return Vector(B.x-A.x, B.y-A.y); } // 向量生成   A-B;

double operator * (Vector A, Vector B){ return A.x*B.x-A.y*B.y;          } // 点积

double operator ^ (Vector A, Vector B){ return A.x*B.y-A.y*B.x;          } // 叉积*/

double Dot(Vector A, Vector B)   { return A.x*B.x + A.y*B.y; }  // 点积

double Cross(Vector A, Vector B) { return A.x*B.y-A.y*B.x;   }  // 叉积

double Length(Vector A)          { return sqrt(Dot(A, A));   } // 向量长度

double dis(Point a,Point b) { return sqrt( (a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y) ); }

Point   pa[maxn];

Point   pb[maxn];

Line    sg[maxn];

int n;

double make(Line A,Line B)

{

    Point a=A.a; Point b=A.b;Point c=B.a; Point d=B.b;

    double A1=b.y-a.y,B1=-(b.x-a.x),C1=b.y*a.x-b.x*a.y;

    double A2=d.y-c.y,B2=-(d.x-c.x),C2=d.y*c.x-d.x*c.y;

    double k=A1*B2-A2*B1;

    double x=-(B1*C2-C1*B2)*1.000000000/k;

    double y=(A1*C2-C1*A2)*1.00000000/k;

    return x;

}

bool co(Line A,Line B)

{

    Point  a=A.a; Point  b=A.b; Point  c=B.a;  Point  d=B.b;

    Vector x,y,xxx,yyy;

    x.x=c.x-a.x;    x.y=c.y-a.y;

    y.x=d.x-a.x;    y.y=d.y-a.y;

    xxx.x=c.x-b.x;  xxx.y=c.y-b.y;

    yyy.x=d.x-b.x;  yyy.y=d.y-b.y;

    if( Cross(x,y)*Cross(xxx,yyy)>eps ) return ;

    else return ;

}

double work(Point xx,Point yy)

{

    Line  qq; qq.a=xx;  qq.b=yy;

    //cout<<xx.x<<"  "<<xx.y<<endl;

    //cout<<yy.x<<"  "<<yy.x<<endl;

    double ans=-1e18;

    for(int i=;i<=n;i++)

    {

        if(i==)

        {

            if(co(sg[i],qq)==) return ans;

        }

        else

        {

             if(co(sg[i],qq)==)  ans=max(ans,make(sg[i],qq));

             else

             {

                 if(co(Line(pa[i],pa[i-]),qq)==) ans=max(ans,make(Line(pa[i],pa[i-]),qq));

                 if(co(Line(pb[i],pb[i-]),qq)==) ans=max(ans,make(Line(pb[i],pb[i-]),qq));

                 break;

             }

        }

    }

    return ans;

}

bool up(Point a,Point b)

{

    return a.x<b.x;

}

int main()

{

    while()

    {

        scanf("%d",&n);  if(n==) { break; }

        for(int i=;i<=n;i++) { scanf("%lf %lf",&pa[i].x,&pa[i].y);    }  // xia mian  dian

        sort(pa+,pa++n,up);

        for(int i=;i<=n;i++) { pb[i].x=pa[i].x; pb[i].y=pa[i].y+1.0;  }  // shang mian dian

        for(int i=;i<=n;i++) { pa[i].y--;       pb[i].y--;            }  // 下移

        for(int i=;i<=n;i++) { sg[i].a=pa[i];   sg[i].b=pb[i];        }  //  a xiao b shang

        double ans=-1e18;

        for(int i=;i<=n;i++)

        {

            for(int j=i+;j<=n;j++) // end

            {

                ans=max(ans,work(pa[i],pa[j]));

                ans=max(ans,work(pa[i],pb[j]));

                ans=max(ans,work(pb[i],pa[j]));

                ans=max(ans,work(pb[i],pb[j]));

            }

            //cout<<ans<<endl;

        }

        if(fabs(ans-pa[n].x)>eps ) printf("%.2f\n",ans);

        else printf("Through all the pipe.\n");

    }

    return ;

}