#include <fstream>
#include <iostream>
#include <vector>
using namespace std;

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

vector < vector <unsigned int> > graf;
vector <bool> vizitat;
int n, m, numar_Comp;

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

void dfs(int nod){
    vector<unsigned int>::iterator it;
    for(it = graf[nod].begin(); it != graf[nod].end(); ++it){
        if(!vizitat[*it]){
            vizitat[*it] = 1;
            dfs(*it);
        }
    }
}

int main(){
    citire();
    vizitat.resize(n+1, 0);
    for(int i = 1; i <= n; ++i)
        if(!vizitat[i]){
            dfs(i);
            ++numar_Comp;
        }
    g << numar_Comp;
    g.close();

    return 0;
}