#include <bits/stdc++.h>

using namespace std;

ifstream fin ("dfs.in");
ofstream fout ("dfs.out");

int n, m;


/**

Matrice de adiacenta


6 3
1 2
1 4
3 5

  1 2 3 4 5
1 0 1 0 1 0
2 1 0 0 0 0
3 0 0 0 0 1
4 1 0 0 0 0
5 0 0 1 0 0


Liste de adiacenta


1: 2 4
2: 1
3: 5
4: 1
5: 3

*/


vector < vector <int > > adj;
vector <int> viz;


void DFS(int nod) {
    viz[nod] = 1;
    for (int i : adj[nod])
        if (viz[i] == 0)
            DFS(i);
}

int main()
{
    int cnt = 0; /// numarul de componente conexe
    fin >> n >> m;
    adj.resize(n + 5);
    viz.resize(n + 5);
    for (int i = 1; i <= m; i++) {
        int x, y;
        fin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    for (int i = 1; i <= n; i++)
        if  (viz[i] == 0) {
            DFS(i);
            cnt++;
        }
    fout << cnt << "\n";
    return 0;
}