#include <iostream>
#include <vector>
#include <fstream>

std::vector<int>* L;
std::vector<bool> viz;

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

void DFS(int i)
{
	viz[i] = 1;
	for (auto e : L[i])
		if (!viz[e])
			DFS(e);
}

int main()
{
	int n, m, x, y;
	fin >> n >> m;
	L = new std::vector<int>[n+1];
	for (int i = 1; i <= m; i++)
	{
		fin >> x >> y;
		L[x].push_back(y);
		L[y].push_back(x);
	}
	viz.resize(n+1, 0);
	x = 0;
	for (int i = 1; i <= n; i++)
		if (!viz[i])
		{ x++; DFS(i); } 
	fout << x;
	return 0;
}