1 #include <cstdio>
 2 #include <cstring>
 3 #include <cmath>
 4 #include <algorithm>
 5 #define MAX 100
 6 using namespace std;
 7 
 8 const double eps=1e-3;
 9 
10 int p[MAX];
11 int n;
12 int dcmp(double x){
13     if(fabs(x)<eps) return 0;
14     return x>0 ? 1 : -1;
15 }
16 
17 typedef struct Point{
18     double x,y;
19     Point(double x=0,double y=0):x(x),y(y){}
20 }Point;
21 
22 Point s[MAX];
23 int id[MAX];
24 
25 typedef struct edge{
26     int a,b;
27     double l;
28 
29     bool operator < (const edge& o)const{
30         return dcmp(l-o.l)<0;
31     }
32 
33 }edge;
34 
35 edge e[MAX*MAX];
36 int tot;
37 
38 double dist(Point a,Point b){
39     return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y));
40 }
41 
42 int findset(int x){ return p[x]==x ? p[x] : p[x]=findset(p[x]);}
43 
44 
45 
46 int main()
47 {
48     int t,co;
49     double ans,minn;
50     //freopen("data.txt","r",stdin);
51     scanf("%d",&t);
52     while(t--){
53         scanf("%d",&n);
54         for(int i=0;i<n;i++){
55             scanf("%lf %lf",&s[i].x,&s[i].y);
56         }
57         tot=0;
58         for(int i=0;i<n;i++){
59             for(int j=i+1;j<n;j++){
60                 double l=dist(s[i],s[j]);
61                 e[tot].a=i; e[tot].b=j; e[tot].l=l;
62                 tot++;
63             }
64         }
65         sort(e,e+tot);
66         minn=1e12;
67         for(int i=0;i<n;i++){
68             ans=0;
69             for(int j=0;j<n;j++){
70                 p[j]=j;
71             }
72             co=0;
73             for(int j=0;j<tot && co!=n-2;j++){
74                 if(e[j].a==i || e[j].b==i) continue;
75                 int a=findset(e[j].a),b=findset(e[j].b);
76                 if(p[a]!=p[b]){
77                     p[b]=p[a];
78                     ans+=e[j].l;
79                     co++;
80                 }
81             }
82             minn=min(ans,minn);
83         }
84         if(n==1) minn=0;
85         printf("%.2lf\n",minn);
86     }
87     return 0;
88 }