#include <fstream>
#include <vector>

using namespace std;

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

const int NMAX = 100005;

vector <int> X[NMAX];

int N,M;
int Conexe;
bool Viz[NMAX];

void DFS(int nod)
{
    Viz[nod]=1;
    for(unsigned int i=0;i<X[nod].size();i++){
        int Curent=X[nod][i];
        if(!Viz[Curent]){
            DFS(Curent);
        }
    }
}

int main()
{
    f>>N>>M;
    while(M){
        int i,j;
        f>>i>>j;
        X[i].push_back(j);
        X[j].push_back(i);
        M--;
    }
    for(int i=1;i<=N;i++){
        if(!Viz[i]){
            DFS(i);
            Conexe++;
        }
    }
    g<<Conexe;
    f.close();
    g.close();
    return 0;
}