#include <cstdio>

 #include <iostream>

 #include <algorithm>

 #include <cstring>

 #include <vector>

 #include <cmath>

 using namespace std;

 const double EPS = 1e-;

 const int N = ;

 inline int sgn(double x) { return (x > EPS) - (x < -EPS);}

 struct Point {

     double x, y;

     Point() {}

     Point(double x, double y) : x(x), y(y) {}

     bool operator < (Point a) const { return sgn(x - a.x) <  || sgn(x - a.x) ==  && y < a.y;}

     bool operator == (Point a) const { return sgn(x - a.x) ==  && sgn(y - a.y) == ;}

     Point operator + (Point a) { return Point(x + a.x, y + a.y);}

     Point operator - (Point a) { return Point(x - a.x, y - a.y);}

     Point operator * (double p) { return Point(x * p, y * p);}

     Point operator / (double p) { return Point(x / p, y / p);}

 } ;

 typedef Point Vec;

 inline double dot(Vec a, Vec b) { return a.x * b.x + a.y * b.y;}

 inline double cross(Vec a, Vec b) { return a.x * b.y - a.y * b.x;}

 inline double veclen(Vec x) { return sqrt(dot(x, x));}

 inline Point vecunit(Vec x) { return x / veclen(x);}

 inline Point normal(Vec x) { return Point(-x.y, x.x) / veclen(x);}

 struct Line {

     Point s, t;

     Line() {}

     Line(Point s, Point t) : s(s), t(t) {}

     Vec vec() { return t - s;}

     Point point(double p) { return s + vec() * p;}

 } ;

 Point up[N], dw[N];

 Line ul[N], dl[N];

 inline Point llint(Point P, Vec u, Point Q, Vec v) { return P + u * (cross(v, P - Q) / cross(u, v));}

 bool tstcross(Point a, Point b, Point c, Point d) { return sgn(cross(a - c, b - c)) * sgn(cross(a - d, b - d)) > ;}

 double cal(Point s, Point t, int n) {

     Line tl = Line(s, t);

     if (tstcross(tl.s, tl.t, up[], dw[])) return -1e100;

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

         if (tstcross(tl.s, tl.t, up[i + ], dw[i + ])) {

             double ret = -1e100;

             if (!tstcross(tl.s, tl.t, ul[i].s, ul[i].t)) {

                 Point tp = llint(tl.s, tl.vec(), ul[i].s, ul[i].vec());

                 ret = max(ret, tp.x);

             }

             if (!tstcross(tl.s, tl.t, dl[i].s, dl[i].t)) {

                 Point tp = llint(tl.s, tl.vec(), dl[i].s, dl[i].vec());

                 ret = max(ret, tp.x);

             }

             return ret;

         }

     }

     return 1e100;

 }

 void work(int n) {

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

         ul[i] = Line(up[i], up[i + ]);

         dl[i] = Line(dw[i], dw[i + ]);

     }

     double ans = -1e100;

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

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

             if (ans >= 1e99) break;

             ans = max(ans, cal(up[i], dw[j], n));

             ans = max(ans, cal(dw[i], up[j], n));

         }

     }

     if (ans >= 1e99) puts("Through all the pipe.");

     else printf("%.2f\n", ans);

 }

 int main() {

 //    freopen("in", "r", stdin);

     int n;

     while (~scanf("%d", &n) && n) {

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

             scanf("%lf%lf", &up[i].x, &up[i].y);

             dw[i] = Point(up[i].x, up[i].y - 1.0);

         }

         work(n);

     }

     return ;

 }