#include <iostream>
#include <fstream>
#include <vector>
#include nmax 100005
using namespace std;

void dfs(int x) {
	seen[x] = true;
	for(int i=0; i<v[x].size(); i++)
		if(!seen[v[x][i]]) dfs(v[x][i]);
}

int main() {
	ifstream f("dfs.in");
	ofstream g("dfs.out");

	f>>n>>m;
	for(int i=1; i<=m; i++) {
		f>>a>>b;
		v[a].push_back(b);
		v[b].push_back(a);
	}

	for(int i=1; i<=n; i++)
		if(!seen[i]) dfs(i), sol++;

	g<<sol<<"\n";
	return 0;
}