#include<fstream>
#include<vector>
using namespace std;
vector< vector<int> > mat(100001);
vector<int> viz(100001);
int n,cpc,m;
void dfs(int x)
{
	viz[x]=1;
	for(int i=0;i<mat[x].size();++i)
		if(!viz[mat[x][i]])
			dfs(mat[x][i]);
}
int main()
{
	ifstream fin("dfs.in");
	ofstream fout("dfs.out");
	fin>>n>>m;
	for(;m;--m)
	{
		int x,y;
		fin>>x>>y;
		mat[x].push_back(y);
		mat[y].push_back(x);
	}
	for(int i=1;i<=n;++i)
		if(!viz[i])
		{
			++cpc;
			dfs(i);
		}
	fout<<cpc;
}