#include<fstream>
#include<vector>

#define dmax 100003

using namespace std;

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

int n, m, cc, color[dmax];
vector<int>v[dmax];

void dfs(int x)
{
	vector<int>::iterator it;

	color[x] = 1;

	for(it = v[x].begin(); it < v[x].end(); it++)
		if(color[*it] == 0)
		{
			dfs(*it);
		}
	color[x] = 2;	
}	



int main()
{
	in>>n>>m;
	
	for(int i=1; i<=m; i++)
	{
		int v1, v2;	
		
		in>>v1>>v2;
		
		v[v1].push_back(v2);
		v[v2].push_back(v1);
	}
	in.close();
	
	for(int i=1; i<=n; i++)
		if(color[i] == 0)
		{
			cc++;
			dfs(i);
		}	
		
	out<<cc;

	out.close();
	return 0;
}