#include <iostream>
#include <fstream>
#include <vector>
#define nmax 100005

using namespace std;

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

vector <vector <int> > a(nmax);
int viz[nmax];
int n, m, nr;

void citire()
{
    f>>n>>m;
    int x, y;
    for(int i=1; i<=m; ++i)
    {
        f>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
}

void dfs(int nod)
{
    viz[nod]=1;
    for(int i=0; i<a[nod].size(); ++i)
    {
        if(viz[a[nod][i]]==0)
        {
            dfs(a[nod][i]);
        }
    }
}

int main()
{
    citire();
    for(int i=1; i<=n; ++i)
    {
        if(viz[i]==0)
        {
            ++nr;
            dfs(i);
        }
    }
    g<<nr;
    return 0;
}