#include <iostream>
#include <fstream>
#include <queue>
#include <string.h>

using namespace std;

#define MAX_DIM 100005
#define INF 20000000

std::vector <int> G[MAX_DIM];
int N, M;
int visit[MAX_DIM];

int explorare(int node)
{
	visit[node] = 1;
	for(int i = 0; i < G[node].size(); i++) {
		visit[G[node][i]] = 1;
		explorare(G[node][i]);
	}
}

int main()
{
	ifstream inFile("dfs.in");
	ofstream outFile("dfs.out");

	inFile >> N >> M;
	int x, y;
	for(int i = 1; i <= M; i++) {
		inFile >> x >> y;
		G[x].push_back(y);
		G[y].push_back(x);
	}
	
	int ct = 0;
	for(int i = 1; i <= N; i++) {
		if( !visit[i] ) {
			ct++;
			explorare(i);
		}
	}

	outFile << ct;

}