//
//  main.cpp
//  Playground
//
//  Created by Stefan Iarca on 1/22/15.
//  Copyright (c) 2015 Stefan Iarca. All rights reserved.
//

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

#define NMAX 100005

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

int N,M;
bool Used[NMAX];
vector<int> G[NMAX];
int Count;

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

void DFS(int Nod){
    Used[Nod] = true;
    for (int i = 0; i < G[Nod].size(); i++) {
        if (!Used[G[Nod][i]]) {
            DFS(G[Nod][i]);
        }
    }
}

void Solve(){
    for (int i = 1; i <= N; i++) {
        if (!Used[i]) {
            DFS(i);
            Count++;
        }
    }
}

void Write(){
    g<<Count;
}

int main() {
    
    Read();
    Solve();
    Write();
    
    return 0;
}