1 #include<cstdio>
 2 #include<cmath>
 3 #include<cstring>
 4 #include<stdlib.h>
 5 #include<algorithm>
 6 using namespace std;
 7 const int MAXN=10000+5000;
 8 struct point
 9 {
10     int x;
11     int y;
12 }po[MAXN];
13 
14 struct node
15 {
16     int star;
17     int en;
18     double dis;
19     bool operator<(const node&B)const
20     {
21         return dis<B.dis;
22     }
23 }a[MAXN];
24 int p[MAXN];
25 int Find(int x)
26 {
27     return p[x]==x?x:p[x]=Find(p[x]);
28 }
29 
30 double distans(int x1,int y1,int x2,int y2)
31 {
32     return sqrt((double)(x1-x2)*(x1-x2)+(double)(y1-y2)*(y1-y2));
33 }
34 
35 int main()
36 {
37     //freopen("in.txt","r",stdin);
38     int kase;
39     scanf("%d",&kase);
40     while(kase--)
41     {
42         int n,cnt=1;
43         double ans=0;
44         scanf("%d",&n);
45         for(int i=1;i<=n;i++)
46             scanf("%d %d",&po[i].x,&po[i].y);
47         for(int i=1;i<n;i++)
48         {
49             for(int j=i+1;j<=n;j++)
50             {
51                 double temp=distans(po[i].x,po[i].y,po[j].x,po[j].y);
52                 if(10.0<=temp&&temp<=1000.0)
53                 {
54                     a[cnt].star=i;
55                     a[cnt].en=j;
56                     a[cnt].dis=temp;
57                     cnt++;
58                 }
59             }
60         }
61         sort(a+1,a+cnt+1);
62         for(int i=1;i<=cnt;i++)
63             p[i]=i;
64         int sum=0;
65         for(int i=1;i<=cnt;i++)
66         {
67             int x=Find(a[i].star);
68             int y=Find(a[i].en);
69             //printf("x=%d,y=%d",x,y);
70             if(x!=y)
71             {
72                 p[x]=y;
73                 ans+=a[i].dis;
74                 sum++;
75                 if(sum==n-1)
76                     break;
77             }
78         }
79         //printf("%d",sum);
80         if(sum==n-1)
81             printf("%.1lf\n",ans*100);
82         else
83             printf("oh!\n");
84     }
85     return 0;
86 }