#include <iostream>
#include <fstream>
#include <stdio.h>
#include <vector>
 
using namespace std;




void dfs(int source, vector< vector<int> > &lista, int visited[]){
	visited[source] = 1;
	
	for(int i=0; i<lista[source].size(); i++)
		if(visited[lista[source][i]] == 0)
			dfs(lista[source][i], lista, visited);
			
}
 
int main()
{
    int n,m,x,y;
    ifstream in("dfs.in");
    
    in >> n >> m;

    vector< int > aux;   
    vector< vector <int> > lista(n+1, aux);
    
    for(int i=0; i<m; i++){
    	in>>x>>y;
    	lista[x].push_back(y);
    	lista[y].push_back(x);
    }
    
    in.close();

    x=0;
    
    int visited[n+1];
    for(int i=0; i<=n; i++)
    	visited[i] = 0;
    
    for(int i=1; i<=n; i++){
    	if(visited[i] == 0){
    		dfs(i, lista, visited);
    		x++;
    	}
    }
    
    ofstream out("dfs.out");
    out<<x;
    out.close();
    
    return 0;
 
}