#include <fstream>
#include <vector>
#define Nmax 100001

using namespace std;

int viz[Nmax];
vector < int > A[Nmax];

void dfs(int x)
{
	viz[x] = 1;
	vector <int>::iterator it;
	for (it = A[x].begin(); it != A[x].end(); ++it)
		if (!viz[*it])
			dfs(*it);
}

int main()
{
	int n, m, a, b;
	ifstream fin("dfs.in");
	ofstream fout("dfs.out");

	fin>>n>>m;

	for (int i = 0; i < m; ++i)
	{
		fin>>a>>b;
		A[a].push_back(b);
		A[b].push_back(a);
	}

	int sol = 0;
	for (int i = 1; i <= n; ++i)
		if (!viz[i])
		{
			dfs(i);
			++sol;
		}
	fout<<sol<<endl;
	return 0;
}