#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>

using namespace std;

#define maxN 100005
#define PB push_back

vector <int> V[maxN];
bool viz[maxN];
int N , M;

void DFS (int root)
{
	viz[root] = true;
	
	for (unsigned int i = 0 ; i < V[root].size() ; ++i)
	{
		int node = V[root][i];
		
		if (viz[node])
			continue;
		
		DFS(node);
	}
}

int main ()
{
	freopen ("dfs.in" , "r" , stdin);
	freopen ("dfs.out" , "w" , stdout);
	
	scanf ("%d %d" , &N , &M);
	
	int a , b;
	
	while (M --)
	{
		scanf ("%d %d" , &a , &b);
		
		V[a].PB(b);
		V[b].PB(a);
	}
	
	int comp = 0;
	
	for (int i = 1 ; i <= N ; ++i)
	{
		if (viz[i])
			continue;
		
		DFS(i);
		++comp;
	}
	
	printf ("%d" , comp);
	
	return 0;
}