#include <fstream>
#include <vector>

#define MaxN 100005
#define WHITE 0
#define GRAY  1
#define BLACK 2

using namespace std;

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

int N, M, conexes, color[MaxN];
vector<int> neighbours[MaxN];

void dfs(int v) {
	color[v] = GRAY;

	for (int i = 0; i < neighbours[v].size(); ++i) {
		int u = neighbours[v][i];
		if (color[u] == WHITE) {
			dfs(u);
		}
	}
	color[v] = BLACK;
}

int main() {
	fin >> N >> M;

	for (int i = 0; i < M; ++i) {
		int x, y;
		fin >> x >> y;
		neighbours[x].push_back(y);
		neighbours[y].push_back(x);
	}

	for (int i = 1; i <= N; ++i) {
		if (color[i] == WHITE) {
			++conexes;
			dfs(i);
		}
	}	

	fout << conexes << '\n';

	return 0;
}