題意就是 給出n對關係，假如A和B認識，B和C認識，那麼A和B認識。現在互相認識的人可以在一桌吃飯，不互相認識的人可以一桌吃飯，問需要多少張桌子

#pragma GCC optimize(2)
#include<stdio.h>
#include<algorithm>
#include<string.h>
#include<queue>
using namespace std;
const int maxn = 1050;
const int inf = 0x3f3f3f3f;
typedef long long ll;
int f[maxn];
vector<int>vec;
int t, n, m;
int find(int x)
{
	if (x == f[x])
	{
		return f[x];
	}
	else
	{
		return f[x] = find(f[x]);
	}
}
void vj(int u, int v)
{
	int x = find(u);
	int y = find(v);
	if (x != y)
	{
		f[x] = y;
	}
}
int main()
{
	//freopen("C://input.txt", "r", stdin);
	scanf("%d", &t);
	while (t--)
	{
		int cnt = 0;
		vec.clear();
		for (int i = 0; i <= 1040; i++)
		{
			f[i] = i;
		}
		scanf("%d%d", &n, &m);
		for (int i = 1; i <= m; i++)
		{
			int u, v;
			scanf("%d%d", &u, &v);
			vj(u, v);
		}
		for (int i = 1; i <= n; i++)
		{
			if (find(i) == i)
			{
				cnt++;
			}
		}
		printf("%d\n", cnt);
	}
	return 0;
}