// Include
#include <fstream>
#include <vector>
using namespace std;

// Definitii
#define pb push_back

// Constante
const int sz = (int)1e5+1;

// Functii
void dfs(int node);

// Variabile
ifstream in("dfs.in");
ofstream out("dfs.out");

int nodes, edges;
int answer;

int visited[sz];
vector<int> graph[sz];

// Main
int main()
{
	in >> nodes >> edges;
	
	int rFrom, rTo;
	while(edges--)
	{
		in >> rFrom >> rTo;
		graph[rFrom].pb(rTo);
		graph[rTo].pb(rFrom);
	}
	
	for(int i=1 ; i<=nodes ; ++i)
	{
		if(visited[i])
			continue;
		visited[i] = true;
		dfs(i);
		++answer;
	}
	
	out << answer << '\n';
	
	in.close();
	out.close();
	return 0;
}

void dfs(int node)
{
	vector<int>::iterator it, end=graph[node].end();
	for(it=graph[node].begin() ; it!=end ; ++it)
	{
		if(visited[*it])
			continue;
		visited[*it] = true;
		dfs(*it);
	}
}