这题只能说 我觉得很难 而且难到靠北，靠班上的牛人想法 AC 了
//============================================================================
// Name : 6044 - Unique Path.cpp
// Date : 2013/3/17 下午3:35:38
// Author : GCA
//============================================================================
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <climits>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <cctype>
#include <utility>
using namespace std;
#ifdef ONLINE\_JUDGE
#define ll "%lld"
#else
#define ll "%I64d"
#endif
typedef unsigned int uint;
typedef long long int Int;
#define Set(a,s) memset(a,s,sizeof(a))
#define Write(w) freopen(w,"w",stdout)
#define Read(r) freopen(r,"r",stdin)
#define Pln() printf("\\n")
#define I\_de(x,n)for(int i=0;i<n;i++)printf("%d ",x\[i\]);Pln()
#define De(x)printf(#x"%d\\n",x)
#define For(i,x)for(int i=0;i<x;i++)
#define CON(x,y) x##y
#define Pmz(dp,nx,ny)for(int hty=0;hty<ny;hty++){for(int htx=0;htx<nx;htx++){\\
printf("%d ",dp\[htx\]\[hty\]);}Pln();}
#define M 10011
#define PII pair<int,int\>
#define PB push\_back
#define oo INT\_MAX
#define Set\_oo 0x3f
#define Is\_debug true
#define debug(...) if(Is\_debug)printf("DEBUG: "),printf(\_\_VA\_ARGS\_\_)
#define FOR(it,c) for(\_\_typeof((c).begin()) it=(c).begin();it!=(c).end();it++)
#define eps 1e-6
bool xdy(double x,double y){return x>y+eps;}
bool xddy(double x,double y){return x>y-eps;}
bool xcy(double x,double y){return x<y-eps;}
bool xcdy(double x,double y){return x<y+eps;}
int min3(int x,int y,int z){
int tmp=min(x,y);
return min(tmp,z);
}
int max3(int x,int y,int z){
int tmp=max(x,y);
return max(tmp,z);
}
int dis\[M\],low\[M\],t;
int test;
int n,m;
bool isbridge\[M\]\[M\];
int died\[M\];
vector<int\> mz\[M\];
vector<int\> SaveDie;
void dfs(int p,int i){
// debug("run?");
dis\[i\]=low\[i\]=++t;
int child=0;
FOR(it,mz\[i\]){
int u=(\*it);
if(u!=p){
if(dis\[u\]){
low\[i\]=min(low\[i\],dis\[u\]);
}
else{
child++;
dfs(i,u);
low\[i\]=min(low\[i\],low\[u\]);
if(low\[u\]>dis\[i\]){
isbridge\[i\]\[u\]=isbridge\[u\]\[i\]=true;
// debug("%d %d is bridge\\n",i,u);
}
}
}
}
}
//int q\[M\*M\],front,rear;
int vis\[M\];
void bfs\_die(int i){
queue<int\> q;
// front=rear=0;
// q\[front++\]=i;
q.push(i);
vis\[i\]=1;
while(!q.empty()){
int u=q.front();q.pop();
FOR(it,mz\[u\]){
int v=(\*it);
if(!vis\[v\]&&!isbridge\[u\]\[v\]){
// q\[front++\]=v;
q.push(v);
vis\[v\]=1;
SaveDie.PB(v);
SaveDie.PB(u);
}
}
}
FOR(it,SaveDie){
// debug("Die %d\\n",\*it);
died\[\*it\]=1;
}
}
int cnt;
void bfs(int i){
queue<int\> q;
q.push(i);
vis\[i\]=1;
while(!q.empty()){
int u=q.front();q.pop();
FOR(it,mz\[u\]){
int v=(\*it);
if(!vis\[v\]&&!died\[v\]){
q.push(v);
vis\[v\]=1;
cnt++;
}
}
}
// debug("cnt %d\\n",cnt);
}
inline int cn2(int n){
return (n\*(n-1))/2;
}
void solve(){
Set(dis,0);
Set(low,0);
Set(died,0);
Set(isbridge,0);
t=0;
for(int i=1;i<=n;i++){
if(!dis\[i\])dfs(i,i);
}
for(int i=1;i<=n;i++){
Set(vis,0);
SaveDie.clear();
if(!died\[i\])bfs\_die(i);
}
Set(vis,0);
int ans=0;
for(int i=1;i<=n;i++){
cnt=1;
if(!died\[i\]){
bfs(i);
ans+=cn2(cnt);
}
}
printf("%d\\n",ans);
}
int main() {
ios\_base::sync\_with\_stdio(0);
int ff=0;
scanf("%d",&test);
while(test--){
scanf("%d%d",&n,&m);
for(int i=0;i<m;i++){
int u,v;
scanf("%d%d",&u,&v);
mz\[u\].PB(v);
mz\[v\].PB(u);
}
printf("Case #%d: ",++ff);
solve();
for(int i=0;i<=n+1;i++){
mz\[i\].clear();
}
}
}