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

using namespace std;

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

const int limita = 100001;
vector <int> muchii[limita];
int vizitat[limita];
int N, M; //N - numarul de noduri M - numarul de muchii

void DFS(int nod)
{
    vizitat[nod] = 1;
    for (unsigned int i = 0; i < muchii[nod].size(); i++)
    {
        int vecin = muchii[nod][i];
        if(!vizitat[vecin])
        {
            vizitat[vecin] = 1;
            DFS(vecin);
        }
    }
    
}

int main()
{
    in >> N >> M;
    int x, y;
    for (int i = 0; i < M; i++)
    {
        in >> x >> y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }

    int conexe = 0;

    for (int i = 1; i <= N; i++)
    {
        if(vizitat[i] == 0)
        {
            DFS(i);
            conexe++;
        }
    }
    
    out << conexe;

    return 0;
}