#include <stdio.h>
#include <vector>

using namespace std;

void dfs (long node, const vector<vector<long> >& ad, vector<bool>& visited)
{
	visited[node] = true;
	int size = ad[node].size();
	for (int i = 0; i < size; i++) {
		if (!visited[ad[node][i]]) {
			dfs(ad[node][i], ad, visited);
		}
	}
}


int main()
{
	freopen("dfs.in", "r", stdin);
	freopen("dfs.out", "w", stdout);
	long n, node1, node2;
	long long m;
	scanf("%ld %lld", &n, &m);
	vector<vector<long> > ad(n + 1, vector<long>());
	vector<bool> visited(n + 1, false);
	for (long long i = 0; i < m; i++) {
		scanf("%ld %ld", &node1, &node2);
		ad[node1].push_back(node2);
		ad[node2].push_back(node1);
	}

	int count = 0;
	for (int i = 1; i <= n; i++) {
		if (!visited[i]) {
			dfs(i, ad, visited);
			count++;
		}
	}

	printf("%d\n", count);
	return 0;
}