#include<fstream>
#include<cstdio>
#include<vector>

using namespace std;

const int MaxN = 100001;

const char InFile[] = "dfs.in";
const char OutFile[] = "dfs.out";

int N,M,Nrc;
bool viz[MaxN];
vector<int>G[MaxN];

void DFS(int nod)
{
	viz[nod] = 1;
	vector<int>::iterator it;
	for( it = G[nod].begin() ; it != G[nod].end() ; ++it )
		if( !viz[*it] )
			DFS(*it);
}

int main()
{
	ifstream fin( InFile );
	ofstream fout( OutFile );
	fin >> N >> M;
	int i,x,y;
	for( i = 0 ; i < M ; ++i )
		{
			fin >> x >> y;
			G[x].push_back(y);
			G[y].push_back(x);
		}
	Nrc = 0;
	for( i = 1 ; i <= N ; ++i )
		if( !viz[i] )
			{
				++Nrc;
				DFS(i);
			}
	fout << Nrc << '\n';
	fin.close();
	fout.close();
	return 0;
}