#include <bits/stdc++.h>
using namespace std;
map<int, vector<int> >adj;
map<int, int>visited;
map<int,int>::iterator it;
int cnt1,cnt2;
void bfs(int s)
{
    queue<int>q;
    q.push(s);
    visited[s]=1;
    while(!q.empty())
    {
        int u=q.front();
        //cout<<u<<" ";
        q.pop();
        for(int i=0 ; i< adj[u].size() ; i++ )
        {
            if(visited[adj[u][i]]==0)
            {
                if(visited[u]==2)
                {
                    int v=adj[u][i];
                    // cout<<u<<endl;
                    visited[v]=1;
                    q.push(v);
                }
                else if(visited[u]==1)
                {
                    int v=adj[u][i];
                    visited[v]=2;
                    q.push(v);
                }
            }
        }
    }

}
int main()
{
    int t,cs=1;
    cin>>t;
    while(t--)
    {
        int n,edge,n1,n2,cnn1=0,cnt2=0;
        visited.clear();
        cin>>edge;
        vector<int>s;
        s.clear();
        int p;
        for(int i=1; i<=edge; i++)
        {
            cin>>n1>>n2;
            s.push_back(n1);
            s.push_back(n2);
            adj[n1].push_back(n2);
            adj[n2].push_back(n1);
            p=n1;
        }
        bfs(p);
        printf("Case %d: ",cs++);
        for(int i=0; i<s.size(); i++)
        {
            if(visited[s[i]]==0)
            {
                bfs(s[i]);
            }
        }

        for(it=visited.begin() ; it!=visited.end() ; it++ )
        {
           // cout<<it->first<<" "<<it->second<<endl;
            if(it->second==1)
            {
                cnt1++;
            }
            else if(it->second==2)
            {
                cnt2++;
            }
        }
        cout<<max(cnt1,cnt2)<<endl;
        cnt1=0;
        cnt2=0;
    }

    return 0;
}