#include <fstream>
#include <vector>
#include <algorithm>
#include <queue>
#include <iostream>

using namespace std;
const int NMAX = (int)1e5 + 5;

void dfs_rec(int nod, int n, vector<int>& parinti, vector<int> adj[]) {
	int vecin;
    for(int i = 0; i < adj[nod].size(); i++) {
		// toti vecinii lui nod
		vecin = adj[nod][i];
		if (parinti[vecin] == 0) {
			parinti[vecin] = nod;
			dfs_rec(vecin, n, parinti, adj);
		}
	}
}

int main() {
    vector<int> adj[NMAX];
    vector<int> parinti(NMAX, 0);
    int n, m;
    
    ifstream fin("dfs.in");
	ofstream fout("dfs.out");
    fin >> n >> m;
    
    for (int i = 1, x, y; i <= m; i++) {
        fin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    
    fin.close();
    
    int nr_coponente_conexe = 0;
    
    for (int nod = 1; nod <= n; nod++) {
        if (parinti[nod] == 0) {
            dfs_rec(nod, n, parinti, adj); // nod = sursa
			nr_coponente_conexe++;
			// nodes sunt toate nodurile
			// adj e lista de adiacenta pentru fiecare nod
        }
    }
	fout << nr_coponente_conexe << endl;
	fout.close();
    
    return 0;
}