#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

const char iname[] = "dfs.in";
const char oname[] = "dfs.out";
const int nmax = 100005;

ifstream fin(iname);
ofstream fout(oname);

int i, j, N, M, viz[nmax], cnt, x, y;
vector<int> Nod[nmax];


void read()
{
	fin >> N;
	fin >> M;
	for(i = 1; i <= M; i ++)
	{
		fin >> x >> y;
		Nod[x].push_back(y);
		Nod[y].push_back(x);
	}
}

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

int main()
{
	read();
	for(i = 1; i <= N; i ++)
	{
		if(!viz[i])
		{
			cnt ++;
			DFS(i);
		}
	}
	fout << cnt;
	return 0;
}