#include <fstream>
#include <vector>
#define Nmax 100005

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

int n, m, cnt;
vector <int> G[Nmax];
bool used[Nmax];

void DFS(int node)
{
	used[node] = true;
	for (vector <int> :: iterator it = G[node].begin(); it != G[node].end(); ++it)
		if (!used[*it])
			DFS(*it);
}

int main()
{
	fin >> n >> m;
	for (int i = 1; i <= m; ++i)
	{
		int a, b;
		fin >> a >> b;
		G[a].push_back(b);
		G[b].push_back(a);
	}
	for (int i = 1; i <= n; ++i)
	{
		if (!used[i])
		{
			++cnt;
			DFS(i);
		}
	}
	fout << cnt << '\n';
	fin.close();
	fout.close();
	return 0;
}