#include <fstream>
#include <vector>
#include <bitset>
int n, m, x, y, connex_components;
std::vector<int> graph[100001];
std::bitset<100001> visited;
void dfs(int vertex)
{
	visited[vertex]=true;
	for (int i=0;i<graph[vertex].size();i++)
	{
		int neighbour=graph[vertex][i];
		if (!visited[neighbour])
			dfs(neighbour);
	}
}
int main()
{
	freopen("dfs.in", "r", stdin);
	freopen("dfs.out", "w", stdout);
	scanf("%d %d", &n, &m);
	for (int i=0;i<m;i++)
	{
		scanf("%d %d", &x, &y);
		graph[x].push_back(y);
		graph[y].push_back(x);
	}
	for (int i=1;i<=n;i++)
		if (!visited[i])
		{
			connex_components++;
			dfs(i);
		}
	printf("%d", connex_components);
}