#include <bits/stdc++.h>

using namespace std;

int n, inp[50];
double mans;
struct point{
    double x, y;

    point(double _x, double _y){
        x = _x;
        y = _y;
    }
};

struct st{
    int x, r;

    st( int _x, int _r){
        x = _x;
        r = _r;
    }
};


double dist(point p1, point p2){
    return hypot(p1.x - p2.x, p1.y - p2.y);
}

double fnc2(vector<point> pt, double &an, double rd){
    double l = 0.0, r = an + r + 10, mid ;
    int fl = 0;
    for(int i=0; i<100; i++){
        mid = (l + r)/2;
        fl = 0;
        for(int j = 0; j<pt.size(); j++){
            if(mid<pt[j].x){
                l = mid; fl = 1;
                break;
            }
            if(dist(pt[j], point(mid, r)) < pt[j].y + rd){
                l = mid;
                fl = 1;
                break;
            }
        }
        if (fl == 0){
            r = mid;
        }
    }
    if(mid + rd > an) an = rd;
    return mid;
}

void fnc(int i, vector<st> &rd, vector<point> &pt, double ans){
    cout<< i << "  " << ans<<endl;
    if(i==n){
        cout << i << endl;
        for(int x = 0 ; x< pt.size(); x++) {

            cout<< " - > " << pt[x].x << " " << pt[x].y<<endl;
        }
        if (ans < mans )mans = ans;
        return;
    }
    double tmp;
    for(int j=0; j<rd.size(); j++){
        if(rd[j].r > inp[i]){
            tmp = rd[j].r ;
            rd[j].r = inp[i];
            pt.push_back(point(rd[j].x, inp[i]));
            fnc(i+1, rd, pt, ans);
            rd[j].r = tmp;
            pt.pop_back();
        }
    }
    double tm = ans;
    double x = fnc2(pt, tm, inp[i]);
    pt.push_back(point(x, inp[i]));
    fnc(i+1, rd, pt, tm);
    pt.pop_back();
}

int main(){
    freopen("input.txt", "r", stdin);
    int nn;
    scanf("%d", &nn);
    for(int i=1; i<=nn; i++){
        scanf("%d", &n);
        for(int j=0; j<n; j++)scanf("%d", &inp[i]);
        vector<st> vc;
        vc.push_back(st(inp[0], inp[0]));
        vector<point>pt;
        pt.push_back(point(inp[0], inp[0]));
        mans = 99999999;
        fnc(1, vc, pt, inp[0]*2.0);
        printf("Case 1: %lf\n", mans);
    }

}