#include<fstream>
#include<vector>

using namespace std;


ifstream fin("dfs.in");
ofstream fout("dfs.out");
int v[100001];
vector <int> lv[100005];
void dfs(int nod)
{	int i;
	v[nod]=1;
	for(i=0;i<lv[nod].size();i++)
		if(!v[lv[nod][i]])dfs(lv[nod][i]);
}

int n,m;

int main()
{
	int i;
	
	fin>>n;
	fin>>m;
	
	for(i=1;i<=m;i++)
	{	
		int x,y;
		fin>>x>>y;
		lv[x].push_back(y);
		lv[y].push_back(x);
	}
	i=1;
	int nr=1;
	dfs(1);
	while(i<=n)if(v[i]==1)i++;
	                else {dfs(i);nr++;}
	
	fout<<nr;
}