#include <bits/stdc++.h>
using namespace std;
const int INF = 0x3f3f3f3f;
 
struct POINT
{
    int x, y;
}point[20];
 
double dp[(1 << 20)];
 
double Dis(int i, int j)
{
    return hypot(point[i].x - point[j].x, point[i].y - point[j].y);
}
 
int main()
{
    //freopen("input.txt", "r", stdin);
    int i, j, n, cases = 0;
    char str[200];
    while (scanf("%d", &n), n)
    {
        n = n * 2;
        for (i = 0; i < n; i++)
            scanf("%s%d%d", str, &point[i].x, &point[i].y);
        dp[0] = 0;
        for (int s = 1; s < (1 << n); s++)
        {
            dp[s] = INF;
            for (i = 0; i < n; i++)
                if (s & (1 << i))
                    break;
            for (j = i + 1; j < n; j++)
                if (s & (1 << j))
                    dp[s] = min(dp[s], Dis(i, j) + dp[s ^ (1 << i) ^ (1 << j)]);
        }
        printf("Case %d: %.2lf\n",++cases, dp[(1 << n) - 1]);
    }
    return 0;
}