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

using namespace std;

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

const int Nlim=100001;
int N,M,insule;
bool vizitat[Nlim];
vector <int> Muchii[Nlim];

void 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);
}
}
void citire(){
    int x,y;
    f>>N>>M;
    for(int i=1;i<=M;i++){
        f>>x>>y;
        Muchii[x].push_back(y);
        Muchii[y].push_back(x);

}
for(int i=1;i<=N;i++){
    if(!vizitat[i]){
            insule++;
        DFS(i);

}}}
int main()
{
citire();
g<<insule;

}