#include<iostream>
#include<vector>
#include<fstream>
#define nmax 100001
using namespace std;
int n,m,viz[nmax],s;
vector <int> v[nmax];
ifstream fin("dfs.in");ofstream fout("dfs.out");
void citire()
{
	int x,y;
	fin>>n>>m;
	
	while(fin>>x>>y)	{v[x].push_back(y);v[y].push_back(x);}
}
void dfs(int x)
{
	int i;
	viz[x]++;
	for(i=0;i<v[x].size();i++)
	{
		if(viz[v[x][i]]==0)
			dfs(v[x][i]);
	}
}
int main()
{
	int i;
	citire();
	for(i=1;i<=n;i++)
	{
		if(viz[i]==0)
		{dfs(i);s++;}
	}
	fout<<s;
	return 0;
}