#include<fstream>
#include<vector>
using namespace std;
int n,m,x,y,nr,i;
vector<vector<int> > mat(100000);
vector<int> viz(100000);
void dfs(int x)
{
	int i;
	viz[x]=1;
	for(i=0;i<mat[x].size();++i)
		if(!viz[mat[x][i]])
			dfs(mat[x][i]);
}	
int main()
{
	ifstream f("dfs.in");
	ofstream g("dfs.out");
	f>>n>>m;
	for(;m;--m)
	{
		f>>x>>y;
		mat[x].push_back(y);
		mat[y].push_back(x);
	}
	for(i=1;i<=n;++i)
	    if(!viz[i])
		{
			++nr;
			dfs(i);
		}
		g<<nr;
}