#include<bits/stdc++.h>
using namespace std;
int n,m,x[355],y[355];
bitset<18>res[18];
int read(){
	int x=0;char ch=getchar();
	while (!isdigit(ch)) ch=getchar();
	while (isdigit(ch)) x=x*10+ch-48,ch=getchar();
	return x;
}
void solve(){
	n=read();m=read();
	for (int i=0;i<m;i++)
		x[i]=read()-1,y[i]=read()-1;
	int ans=n;
	for (int sta=0;sta<1<<n;sta++){
		if (__builtin_popcount(sta)>=ans) continue;
		for (int i=0;i<n;i++) res[i].reset();
		for (int i=0;i<m;i++)
			if (~sta>>x[i]&1)
				res[x[i]].set(y[i]);
		for (int k=0;k<n;k++)
			for (int i=0;i<n;i++) if (res[i][k])
				res[i]|=res[k];
		bool flag=0;
		for (int i=0;i<n;i++)
			for (int j=i+1;j<n;j++)
				if (res[i][j]&&res[j][i])
					flag=1;
		if (!flag) ans=__builtin_popcount(sta);
	}
	printf("%d\n",ans+n);
}
int main(){int T=read();while (T--) solve(); return 0;}