#include <vector>
#include <fstream>
#include <queue>
using namespace std;

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

vector <int> graph[100005];
vector <bool> viz(100005, false);

void dfs(int node){
	viz[node] = true;

	int son;
	for(int i = 0; i < graph[node].size(); i++){
		son = graph[node][i];
		if(!viz[son])
			dfs(son);
	}
}

int main(){
	int n, m;
	f >> n >> m;

	int x, y;
	for(int i = 1; i <= m; i++){
		f >> x >> y;
		graph[x].push_back(y);
		graph[y].push_back(x);
	}

	int nr = 0;
	for(int i = 1; i <= n; i++){
		if(!viz[i]){
			dfs(i);
			nr ++;
		}
	}

	g << nr;
}