#include<bits/stdc++.h>
#define lowbit(x) (x&(-x))
#define rep(x,a,b) for(int x=a;x<=b;x++)
#define pre(x,a,b) for(int x=a;x>=b;x--)
#define endl "\n"
#define pb push_back
#define ll long long
#define int long long
#define pii pair<ll,ll>
#define psi pair<string, ll>
#define de cout<<1;
#define mem(a,x) memset(a,x,sizeof a)
#define IOS ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
using namespace std;
const int mod1=998244353;
const int mod2=1e9+7;
const int INF=1e18;
const int N = 1e6 + 60;
int number;
int n, idx;
double x[110], y[110];
double calc(int i, int j)
{
    return sqrt(abs(x[i] - x[j]) * abs(x[i] - x[j]) + abs(y[i] - y[j]) * abs(y[i] - y[j]));
}
void solve()
{
    while(scanf("%d", &n) != EOF)
    {
        idx ++ ;
        rep(i, 1, n) scanf("%lf%lf", &x[i], &y[i]);
        double ans = 1e9;
        rep(i, 1, n)
        rep(j, i + 1, n)
        {
            if(x[i] == x[j])
            {
                int f = 0, l = 0, r = 0;
                rep(k, 1, 100)
                {
                    if(k == i || k == j) continue;
                    if(x[k] < x[i]) l ++ ;
                    else if(x[k] > x[i]) r ++ ;
                    else
                    {
                        if(y[k] < min(y[i], y[j]) || y[k] > max(y[i], y[j]))
                        {
                            f = 1;
                            break;
                        }
                    }
                }
                if(l == 0 || r == 0) f = 1;
                if(l > 1 && r > 1) f = 1;
                if(f) continue;
                else ans = min(ans, calc(i, j));
            }
            else
            {
                double k = (y[i] - y[j]) / (x[i] - x[j]);
                double b = y[i] - k * x[i];
                int l = 0, r = 0;
                int f = 0;
                rep(w, 1, n)
                {
                    if(w == i || w == j) continue;
                    double yy = k * x[w] + b;
                    if(y[w] > yy) l ++ ;
                    else if(y[w] < yy) r ++ ;
                    else
                    {
                        if(yy > max(y[i], y[w])) f = 1;
                        if(yy < min(y[i], y[w])) f = 1;
                        if(f) break;
                    }
                }
                if(l == 0 || r == 0) f = 1;
                if(l > 1 && r > 1) f = 1;
                if(f) continue;
                ans = min(ans, calc(i, j));
            }
        }
        printf("Case %d: %.4lf\n", idx, ans);
    }
}
signed main()
{
	//IOS;
	int _;
	//scanf("%d", &_);
	_ = 1;
	while(_ -- )
	{
		number++;
		solve();
	}
	return 0;
}