#include <fstream>
#include <vector>

using namespace std;

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

const int NMAX=100005;

vector < int > Muchii[NMAX];
bool Vizitat[NMAX];
int N,M,NR=0;

DFS(int Nod)
{
    Vizitat[Nod]=true;
    for (unsigned int i=0; i<Muchii[Nod].size(); i++)
    {
        int Vecin=Muchii[Nod][i];
        if(!Vizitat[Vecin])
            DFS(Vecin);
    }
}
int main()
{
    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 (int i=1; i<=N; i++)
        if (!Vizitat[i])
 {
        DFS(i);
        NR++;
 }

 fout<<NR<<"\n";
}