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

const int  NMAX = 100000;
vector<int> graf[NMAX];
bool vizitat[NMAX];

void DFS(int x) {
	vizitat[x] = true;
	for (int i = 0; i < graf[x].size(); i++) {
		if (!vizitat[graf[x][i]]) {
			DFS(graf[x][i]);
		}
	}
}

int main() {
	ifstream in("dfs.in");
	ofstream out("dfs.out");
	int n, m, x, y, conexe = 0;
	in >> n >> m;

	for (int i = 0; i < m; i++) {
		in >> x >> y;
		graf[x].push_back(y);
		graf[y].push_back(x);
	}

	/*for (int i = 0; i < n; i++) {
		cout << i << ": ";
		for (int j = 0; j < graf[i].size(); j++) {
			cout << graf[i][j]<<" ";
		}
		cout << endl;
	}*/	

	for (int i = 0; i < n; i++) {
		if (!vizitat[i]) {
			conexe++;
			DFS(i);
		}
	}
	out << conexe;
}