1 #include <iostream>
  2 #include <cstdio>
  3 #include <cstring>
  4 using namespace std;
  5 const int maxn=110;
  6 int edge[maxn][3];
  7 int fa[maxn],cnt=1,fir[maxn],nxt[maxn<<1],to[maxn<<1];
  8 int dep[maxn],pre[maxn],ret[maxn],ID[maxn<<1];
  9 int find(int x)
 10 {
 11     return fa[x]==x?x:fa[x]=find(fa[x]);
 12 }
 13 
 14 void addedge(int a,int b,int id)
 15 {
 16     nxt[++cnt]=fir[a];ID[cnt]=id;
 17     to[cnt]=b;fir[a]=cnt;
 18 }
 19 
 20 void DFS(int node)
 21 {
 22     for(int i=fir[node];i;i=nxt[i])
 23     {
 24         if(dep[to[i]])continue;
 25         dep[to[i]]=dep[node]+1;
 26         pre[to[i]]=i;
 27         DFS(to[i]);
 28     }
 29 }
 30 int Search(int x,int y,int d)
 31 {
 32     while(x!=y){
 33         if(dep[x]<dep[y])
 34             swap(x,y);
 35         ret[ID[pre[x]]]+=d;
 36         x=to[pre[x]^1];
 37     }
 38 }
 39 void Init()
 40 {
 41     memset(fir,0,sizeof(fir));
 42     memset(ret,0,sizeof(ret));
 43     cnt=1;
 44 }
 45 
 46 int main()
 47 {    
 48     freopen("data.in","r",stdin);
 49     freopen("wrong.out","w",stdout);
 50     int T,n;
 51     scanf("%d",&T);
 52     while(T--)
 53     {
 54         Init();
 55         scanf("%d",&n);
 56         for(int i=1;i<=n+1;i++){
 57             fa[i]=i;
 58         }
 59     
 60         for(int i=1;i<=n+1;i++)
 61             scanf("%d%d",&edge[i][0],&edge[i][1]);
 62         for(int i=1;i<=n+1;i++){
 63             int a=find(edge[i][0]),b=find(edge[i][1]);
 64             if(a==b)
 65                 edge[i][2]=1;
 66             else{
 67                 fa[a]=b;
 68                 addedge(edge[i][0],edge[i][1],i);
 69                 addedge(edge[i][1],edge[i][0],i);
 70             }
 71         }
 72         int flag=0;
 73         for(int i=2;i<=n;i++)
 74         if(find(i)!=find(i-1)){
 75             printf("0\n");
 76             flag=1;
 77             break;
 78         }
 79         if(flag==1)continue;
 80         dep[1]=1;
 81         DFS(1);
 82         int ans=0,a=0,b=0,c=0;
 83         for(int i=1;i<=n+1;i++){
 84             if(edge[i][2]){
 85                 if(!ans){
 86                     Search(edge[i][0],edge[i][1],1);
 87                     ret[i]+=1;
 88                 }
 89                     
 90                 else {
 91                     Search(edge[i][0],edge[i][1],10);
 92                     ret[i]+=10;
 93                 }
 94                 ans+=1;    
 95             }
 96         }
 97         for(int i=1;i<=n+1;i++){
 98             if(ret[i]==1)a++;
 99             else if(ret[i]==10)b++;
100             else if(ret[i]==11)c++,b++,a++;
101         }
102         printf("%d\n",a+b-c+(a+b-c-1)*(a+b-c)/2-(a-c)*(a-c-1)/2-(b-c)*(b-c-1)/2-c*(c-1)/2);
103     }
104     return 0;
105 }