#include <cstdio>

 #include <cmath>

 #include <algorithm>

 #include <cfloat>

 using namespace std;

 struct Point

 {

     int x, y;

 } point[];

 double dp[<<+];

 double dis(int a, int b)

 {

     int x_diff = point[a].x - point[b].x;

     int y_diff = point[a].y - point[b].y;

     return sqrt(x_diff * x_diff + y_diff * y_diff);

 }

 int main()

 {

 #ifdef LOCAL

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

 #endif

     int n, kase = ;

     char name[];

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

     {

         n *= ;

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

             scanf("%s%d%d", name, &point[i].x, &point[i].y);

         dp[] = ;

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

         {

             dp[s] = DBL_MAX;

             int p = ;

             for ( ; p < n; p++)

                 if (s & (<<p))  break;

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

                 if (s & (<<i))

                     dp[s] = min(dp[s], dis(p, i)+dp[s^(<<p)^(<<i)]);

         }

         printf("Case %d: %.2lf\n", ++kase, dp[(<<n)-]);

     }

     return ;

 }