#include <iostream>

 #include<cstdio>

 #include<cstring>

 #include<algorithm>

 #include<stdlib.h>

 #include<vector>

 #include<cmath>

 #include<queue>

 #include<set>

 using namespace std;

 #define N 100000

 #define LL long long

 #define INF 0xfffffff

 const double eps = 1e-;

 const double pi = acos(-1.0);

 const double inf = ~0u>>;

 struct point

 {

     double x,y;

     point(double x=,double y = ):x(x),y(y){}

 }p[N];

 typedef point pointt;

 point operator -(point a,point b)

 {

     return point(a.x-b.x,a.y-b.y);

 }

 double cross(point a,point b)

 {

     return a.x*b.y-a.y*b.x;

 }

 int main()

 {

     int i,j,n;

     int kk = ;

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

     {

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

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

         p[n] = p[];

         double sx = ,sy = ,sum = ;

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

         {

             double ts = cross(p[i]-p[],p[i+]-p[])/;

             double x = p[].x+p[i].x+p[i+].x;

             double y = p[].y+p[i].y+p[i+].y;

             sum+=ts;

             sx+=x*ts;

             sy+=y*ts;

         }

         printf("Stage #%d: %.6f %.6f\n",++kk,sx/3.0/sum,sy/3.0/sum);

     }

     return ;

 }