// Parcurgere DFS + Componente Conexe
// http://infoarena.ro/problema/dfs

#include <cstdio>

#include <vector>
using namespace std;

const int NMAX = 100005;

int n, m;
vector<int> Neighb[NMAX];
bool Used[NMAX];

void depthFirst(int n) {
	vector<int>::iterator it;
	for (it = Neighb[n].begin(); it != Neighb[n].end(); ++ it)
		if (Used[*it] == false) {
			Used[*it] = true;
			depthFirst(*it);
		}
}

int main() {

	freopen("dfs.in", "r", stdin);
	scanf("%d %d", &n, &m);
	int i, v1, v2;
	for (i = 0; i < m; ++ i) {
		scanf("%d %d", &v1, &v2);
		-- v1, -- v2;
		Neighb[v1].push_back(v2), Neighb[v2].push_back(v1);
	}

	int ncc = 0;
	for (i = 0; i < n; ++ i)
		if (Used[i] == false) {
			++ ncc;
			Used[i] = true;
			depthFirst(i);
		}

	freopen("dfs.out", "w", stdout);
	printf("%d\n", ncc);

	return 0;
}