#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

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

int n, m;
int insula = 0;

int const lim = 200000;
vector < int > muchii[lim];
bool vizitat[lim];

void dfs(int nod)
{
    vizitat[nod] = true;
    for (unsigned int i=0;i<muchii[nod].size();i++)
    {
        int next = muchii[nod][i];
        if (!vizitat[next])
            dfs(next);
    }
}

void citeste()
{
    fin >> n >> m;
    for (int i=1;i<=m;i++)
    {
        int x,y;
        fin >> x >> y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }
    for (unsigned int i = 1;i<=n;i++)
    {
        if (!vizitat[i])
            {
                insula++;
                dfs(i);
            }

    }
}

int main()
{
    citeste();
    fout << insula;
    return 0;
}