1 #include <iostream>
  2 #include <cstdio>
  3 #include <string>
  4 #include <queue>
  5 #include <vector>
  6 #include <map>
  7 #include <algorithm>
  8 #include <cstring>
  9 #include <cctype>
 10 #include <cstdlib>
 11 #include <cmath>
 12 #include <ctime>
 13 using    namespace    std;
 14 
 15 const    int    SIZE = 105;
 16 int    FATHER[SIZE],N,M,NUM;
 17 int    MAP[SIZE][SIZE];
 18 struct    Node
 19 {
 20     int    from,to;
 21     double    cost;
 22 }G[SIZE * SIZE];
 23 struct
 24 {
 25     int    x,y;
 26 }TEMP[SIZE];
 27 
 28 void    ini(void);
 29 int    find_father(int);
 30 void    unite(int,int);
 31 bool    same(int,int);
 32 void    kruskal(void);
 33 bool    comp(const Node &,const Node &);
 34 double    dis(int,int,int,int);
 35 int    main(void)
 36 {
 37     int    t;
 38     double    temp;
 39 
 40     scanf("%d",&t);
 41     while(t --)
 42     {
 43         scanf("%d",&N);
 44         ini();
 45         for(int i = 1;i <= N;i ++)
 46             scanf("%d%d",&TEMP[i].x,&TEMP[i].y);
 47         for(int i = 1;i <= N;i ++)
 48             for(int j = i + 1;j <= N;j ++)
 49             {
 50                 temp = sqrt(dis(TEMP[i].x,TEMP[i].y,TEMP[j].x,TEMP[j].y));
 51                 if(temp >= 10 && temp <= 1000)
 52                 {
 53                     G[NUM].from = i;
 54                     G[NUM].to = j;
 55                     G[NUM].cost = temp * 100;
 56                     NUM ++;
 57                 }
 58             }
 59         sort(G,G + NUM,comp);
 60         kruskal();
 61     }
 62 
 63     return 0;
 64 }
 65 
 66 void    ini(void)
 67 {
 68     NUM = 0;
 69     for(int i = 1;i <= N;i ++)
 70         FATHER[i] = i;
 71 }
 72 
 73 int    find_father(int n)
 74 {
 75     if(FATHER[n] == n)
 76         return    n;
 77     return    FATHER[n] = find_father(FATHER[n]);
 78 }
 79 
 80 void    unite(int x,int y)
 81 {
 82     x = find_father(x);
 83     y = find_father(y);
 84 
 85     if(x == y)
 86         return    ;
 87     FATHER[x] = y;
 88 }
 89 
 90 bool    same(int x,int y)
 91 {
 92     return    find_father(x) == find_father(y);
 93 }
 94 
 95 bool    comp(const Node & a,const Node & b)
 96 {
 97     return    a.cost < b.cost;
 98 }
 99 
100 void    kruskal(void)
101 {
102     int    count = 0;
103     double    ans = 0;
104 
105     for(int i = 0;i < NUM;i ++)
106         if(!same(G[i].from,G[i].to))
107         {
108             unite(G[i].from,G[i].to);
109             count ++;
110             ans += G[i].cost;
111             if(count == N - 1)
112                 break;
113         }
114     if(count == N - 1)
115         printf("%.1f\n",ans);
116     else
117         puts("oh!");
118 }
119 
120 double    dis(int x_1,int y_1,int x_2,int y_2)
121 {
122     return    pow(x_1 - x_2,2) + pow(y_1 - y_2,2);
123 }