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

#define MAXN 100010

using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

int N, M, nrv[MAXN], viz[MAXN];
vector<int> A[MAXN];

void read()
{
	int x, y;
	
	f >> N >> M;
	for(int i = 0; i < M; ++i)
	{
		f >> x >> y;
		A[x].push_back(y), nrv[x]++;
		A[y].push_back(x), nrv[y]++;
	}
	
	f.close();
}

void dfs(int nod)
{
	viz[nod] = 1;
	for(int i = 0; i < nrv[nod]; ++i)
		if(!viz[A[nod][i]])
			dfs(A[nod][i]);
}

int main()
{
	int cmp = 0;
	read();
	for(int i = 1; i <= N; ++i)
		if(!viz[i])
			cmp++, dfs(i);
			
	g << cmp;
}