#include <iostream>
#include <vector>
#include <fstream>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

int viz[100000+5], ct = 0;

vector <int> adj[100000+5];

void dfs(int nod, int numar)
{
	viz[nod] = numar;
	for(int i = 0; i< adj[nod].size(); ++i)
	{
		if(viz[adj[nod][i]] != 0) continue;
		dfs(adj[nod][i], ct);
	}
}

int main()
{
    int m,n,x,y;
    f >> n >> m;
    for (int i=1;i<=m;i++)
    {
        f >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    for(int i = 1; i<= n; ++i)
{
	if(viz[i] != 0) continue;
	dfs(i, ++ct);
}
    g << ct << "\n";


}