#define IA_PROB "dfs"

#include <cstdio>
#include <string>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <stack>

#include <algorithm>

using namespace std;

int n, m, ncc;
vector< vector<int> > vec;
vector<int> cc;

void dfs(int n, int c)
{
	cc[n] = c;
	for (int i = 0; i < vec[n].size(); i++)
		if (cc[vec[n][i]] == 0)
			dfs(vec[n][i], c);
}

int main()
{
	freopen(IA_PROB".in", "r", stdin);
	freopen(IA_PROB".out", "w", stdout);


	scanf("%d %d", &n, &m);
	ncc = 0;

	vec.resize(n, cc);
	cc.resize(n, 0);

	for (int i = 0; i < m; i++) {
		int x, y;
		scanf("%d %d", &x, &y);
		x--;
		y--;
		vec[x].push_back(y);
		vec[y].push_back(x);
	}

	for (int i = 0; i < n; i++) {
		if (cc[i] == 0) {
			ncc++;
			dfs(i, ncc);
		}
	}
	printf("%d", ncc);

	return 0;
}