#include<iostream>
#include<set>
#include<algorithm>
#include <vector>
#include <fstream>
#include <cstring>
#include <map>
#include <math.h>

using namespace std;

int n, m;
vector<int> v[200002];
vector<int> viz(200002);
int nr;

void dfs (int nod){
    viz[nod] = 1;
    for (int i = 0; i<v[nod].size(); i++){
        if (!viz[v[nod][i]]){
            dfs(v[nod][i]);
        }
    }
}
int main (){

    ifstream cin ("dfs.in");
    ofstream cout ("dfs.out");

    cin >> n >> m;

    for (int i = 1; i<=m; i++){
        int a, b;
        cin >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }

    for (int i = 1; i<=n; i++){
        if (!viz[i]){
            nr++;
            dfs(i);
        }
    }

    cout << nr;
}