#include <cstdio>

#include <cstring>

#include <string>

#include <cmath>

#include <iostream>

#include <algorithm>

#include <queue>

#include <cstdlib>

#include <stack>

#include <vector>

#include <set>

#include <map>

#define LL long long

#define mod 100000000

#define inf 0x3f3f3f3f

#define eps 1e-6

#define N 1010

#define FILL(a,b) (memset(a,b,sizeof(a)))

#define lson l,m,rt<<1

#define rson m+1,r,rt<<1|1

#define PII pair<int,int>

using namespace std;

int match[N],vis[N],n,m;

vector<int>g[N];

int dfs(int u)

{

    for(int i=,sz=g[u].size(); i<sz; i++)

    {

        int v=g[u][i];

        if(!vis[v])

        {

            vis[v]=;

            if(match[v]==-||dfs(match[v]))

            {

                match[v]=u;

                return ;

            }

        }

    }

    return ;

}

int hungary()

{

    FILL(match,-);

    int ans=;

    for(int i=; i<=n; i++)

    {

        FILL(vis,);

        if(dfs(i))ans++;

    }

    return ans;

}

int main()

{

    int T,u,v,cas=;

    scanf("%d",&T);

    while(T--)

    {

        scanf("%d%d",&n,&m);

        for(int i=; i<=n; i++)

            g[i].clear();

        for(int i=; i<=m; i++)

        {

            scanf("%d%d",&u,&v);

            g[u].push_back(v);

            g[v].push_back(u);

        }

        int res=hungary();

        printf("Case %d: %d\n",cas++,n-res/);

    }

}