#include <fstream>
#include <vector>
#define NMAX 100002

using namespace std;

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

int n,nrc,m;
vector<int> G[NMAX];
int uz[NMAX];

void citire();
void dfs(int x);
void afisare ();

int main()
{
    int i;
    citire();
    for (i=1; i<=n; i++)
    {
        if (uz[i]==0)
        {
            nrc++;
            dfs(i);
        }
    }
    afisare ();
    return 0;
}

void citire()
{
    int x,y;
    fin>>n>>m;
    while (fin>>x>>y)
    {
        G[y].push_back(x);
        G[x].push_back(y);
    }
}

void dfs(int x)
{
    int i;
    uz[x]=nrc;
    for (i=0; i<G[x].size(); i++)
    {
        if (uz[G[x][i]]==0)
            dfs(G[x][i]);
    }
}

void afisare ()
{
    int i,j;
    fout<<nrc<<'\n';
}