#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

const int NMAX=1e6;
vector <int> G[NMAX+1];
int viz[NMAX+1],d[NMAX+1];
int n,m;

/*
int a[NMAX+1][NMAX+1];
void CitireMatrice(){
    cin>>n>>m;
    for(int i=1;i<=m;++i) {
        int x, y;
        cin >> x >> y;
        a[x][y] = a[y][x] = 1;
    }
    //Afisare
    for(int i=1;i<=n;++i){
        for(int j=1;j<=m;++j) cout<<a[i][j]<<" ";
        cout<<"\n";
    }
}*/
//Fiind dat un nod S, sa se determine, pentru fiecare nod X,
// numarul minim de arce ce trebuie parcurse pentru a ajunge din nodul sursa S la nodul X.

void CitireListe(){
    fin>>n>>m;
    for(int i=1;i<=m;++i){
        int x,y;
        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

void DFS(int x){
    viz[x]=1;
    for(auto next:G[x])
        if(!viz[next]) DFS(next);
}

void Afisare(){
    for(int i=1;i<=n;++i){
        for(auto v:G[i]) fout<<v<<" ";
        fout<<"\n";
    }
}
int main() {
    //CitireMatrice();
    CitireListe();
    int ct=0;
    for(int i=1;i<=n;++i){
            if(!viz[i]) { ct++; DFS(i);}
        }
    fout<<ct;
    return 0;
}