#include<stdio.h>
int father[1001];
int find(int a)
{
while(father[a]>0)
{
a=father[a];
}
return a;
}
int main()
{
int n,m,t,i,a,b,num;
scanf("%d",&t);
while(t--)
{
num=0;
scanf("%d%d",&m,&n);
for(i=1;i<=m;++i)
father[i]=-1;
for(i=1;i<=n;++i)
{
scanf("%d%d",&a,&b);
a=find(a);
b=find(b);
if(a!=b)
father[a]=b;
}
for(i=1;i<=m;++i)
if(father[i]<0)
++num;
printf("%d\n",num);
}
return 0;
}