1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstring>
 4 
 5 using namespace std;
 6 
 7 int Map[220][220],ok[220],n,m;
 8 int vis[220];
 9 
10 bool Find(int x)
11 {
12     for (int i=1; i<=n; i++)
13     {
14         if (!vis[i]&&Map[x][i])
15         {
16             vis[i]=1;
17             if (!ok[i])
18             {
19                 ok[i]=x;
20                 return true;
21             }
22             else
23             {
24                 if(Find(ok[i]))
25                 {
26                     ok[i]=x;
27                     return true;
28                 }
29             }
30         }
31     }
32     return false;
33 }
34 
35 int main()
36 {
37     int t,ans,a,b;
38     scanf("%d",&t);
39     while (t--)
40     {
41         ans=0;
42         memset(Map,0,sizeof(Map));
43         memset(ok,0,sizeof(ok));
44         scanf("%d%d",&n,&m);
45         for (int i=1; i<=m; i++)
46         {
47             scanf("%d%d",&a,&b);
48             Map[a][b]=1;
49         }
50         for (int i=1; i<=n; i++)
51         {
52             memset(vis,0,sizeof(vis));
53             if (Find(i))
54             {
55                 ans++;
56             }
57         }
58         printf ("%d\n",n-ans);
59     }
60     return 0;
61 }