#include<fstream>
#include<vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

vector<int> g[100005];
int v[100005];

void dfs(int x)
{
	v[x] = 1;
	for (int i = 0; i < g[x].size(); i++)
	{
		if (v[g[x][i]]) continue;
		dfs(g[x][i]);
	}
}

int main () {
	int n, m, nr=0;
	fin >> n >> m;

	for (int i = 1; i <= m; i++)
	{
		int a, b;
		fin >> a >> b;
		g[a].push_back(b);
		g[b].push_back(a);
	}
	for (int i = 1; i <= n; i++)
	{
		if (!v[i]) {
			dfs(i);
			nr++;
		}
	}
	fout << nr;
}