#include<fstream>
#include<iostream>
#include<vector>
#include<bitset>
using namespace std;

#define MAXN 100050
bitset<MAXN> viz;
vector<int> g[MAXN];
typedef vector<int>::iterator iter;
int nivel[MAXN];

void dfs(int nod)
{
	viz[nod] = 1;
	for(iter it = g[nod].begin(); it != g[nod].end(); it++)
		if(!viz[*it])
			dfs(*it);
}

int main()
{
	ifstream in("dfs.in");
	ofstream out("dfs.out");
	
	int n, m;
	in >> n >> m;
	
	for (int i = 1; i <= m; ++i) {
		int x, y;
		in >> x >> y;
		g[x].push_back(y);
		g[y].push_back(x);
	}
	int nr = 0;
	for(int i = 1; i <= n; i++)
	{
		if(!viz[i])
		{
			dfs(i);
			nr++;
		}
	}
	out<<nr;
}