1 #include <cstdio>
 2 #include <cstring>
 3 #include <algorithm>
 4 #include <iostream>
 5 #include <vector>
 6 #include <queue>
 7 #include <map>
 8 #include <cmath>
 9 using namespace std;
10 
11 struct node{
12     int x, y;
13     double w;
14 }a[105*105/2];
15 
16 struct mem{
17     double x, y;
18 }b[105];
19 
20 int father[105];
21 int f[105];
22 int n, m;
23 int ma[105][105];
24 int visited[105];
25 int dis[105];
26 int c[105];
27 
28 int findroot1(int p){
29     int x=p;
30     while(x!=father[x]) x=father[x];
31     return x;
32 }
33 
34 int findroot2(int p){
35     int x=p;
36     while(x!=f[x]) x=f[x];
37     return x;
38 }
39 
40 bool cmp(node a,node b){
41     return a.w<b.w;
42 }
43 
44 main()
45 {
46     int i, j, k;
47     int t;
48     double d;
49     cin>>t;
50     while(t--){
51         scanf("%d",&n);
52         k=0;
53         for(i=0;i<=n;i++) {father[i]=i;f[i]=i;c[i]=1;}
54         for(i=0;i<n;i++) scanf("%lf %lf",&b[i].x,&b[i].y);
55         for(i=0;i<n;i++){
56             for(j=i+1;j<n;j++){
57                 d=sqrt((double)(b[i].x-b[j].x)*(b[i].x-b[j].x)+(double)(b[i].y-b[j].y)*(b[i].y-b[j].y));
58                 if(d>=10&&d<=1000){
59                     a[k].x=i;a[k].y=j;
60                     a[k++].w=d*100.0;
61                     father[findroot1(j)]=findroot1(i);
62                 }
63             }
64         }
65         int num=0;
66         for(i=0;i<n;i++){
67             if(i==findroot1(i))
68             num++;
69         }
70         if(num>1) {
71             printf("oh!\n");continue;
72         }
73         sort(a,a+k,cmp);
74         double ans=0;j=1;
75         for(i=0;i<k;i++){
76             int fx=findroot2(a[i].x);
77             int fy=findroot2(a[i].y);
78             if(fx!=fy){
79                 ans+=a[i].w;
80                 f[fy]=fx;
81                 c[fx]+=c[fy];
82                 if(c[fx]>=n) break;
83             }
84         }
85         printf("%.1lf\n",ans);
86     }
87 }