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

#define NMAX 100001

using namespace std;
int n, m;
vector<int> adList[NMAX];
int visited[NMAX], comp;

void dfs(int node){
	visited[node] = 1;
	vector<int> :: iterator it = adList[node].begin();

	while(it != adList[node].end()){
		if(visited[*it] == 0)
			dfs(*it);
		it++;
	}
}

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

	f >> n >> m;
	for(int i = 0; i < m; i++){
		f >> x >> y;
		adList[x].push_back(y);
		adList[y].push_back(x);
	}

	f.close();

	for(int i = 1; i <= n; i++)
		if(visited[i] == 0){
			dfs(i);
			comp++;
		}
	g << comp;

	g.close();
	return 0;
}