#include<bits/stdc++.h>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n, m, cnt;
vector<int> mt[100005];
bool viz[100005];
void DFS(int nod)
{
	viz[nod] = 1;
	for (auto i : mt[nod])
		if (!viz[i])
			DFS(i);
}
int main()
{
	fin >> n >> m;
	for (int i = 1; i <= m; ++i)
	{
		int x, y;
		fin >> x >> y;
		mt[x].push_back(y);
		mt[y].push_back(x);
	}
	for (int i = 1; i <= n; ++i)
	{
		if (!viz[i])
		{
			++cnt;
			DFS(i);
		}
	}
	fout << cnt;

}