#include <cstdio>#include <cstring>#include <cmath>#include <algorithm>#include <climits>#include <string>#include <iostream>#include <map>#include <cstdlib>#include <list>#include <set>#include <queue>#include <stack>using namespace std;typedef long long LL;const int maxn = 150;int bx[maxn],by[maxn];int n,m;bool g[maxn][maxn],vis[maxn];int dfs(int now) {    for(int i = 1;i <= n;i++) if(!vis[i] && g[i][now]) {        vis[i] = true;        if(!by[i] || dfs(by[i])) {            bx[now] = i; by[i] = now; return 1;        }    }    return 0;}void solve() {    memset(bx,0,sizeof(bx));    memset(by,0,sizeof(by));    int ans = 0;    for(int i = 1;i <= n;i++) if(!bx[i]) {        memset(vis,0,sizeof(vis));        if(dfs(i)) ans++;       }    printf("%d\n",n - ans);}int main() {    int T; cin >> T;    while(T--) {        memset(g,0,sizeof(g));        cin >> n >> m;        for(int i = 0;i < m;i++) {            int a,b; cin >> a >> b;            g[a][b] = true;        }        solve();    }    return 0;}