#include <iostream>
#include <fstream>
#include <vector>
#define Nmax 200005
using namespace std;

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

int N, M;
bool Viz[Nmax];
vector <int> G[Nmax];

void Read()
{
    int x, y;
    fin >> N >> M;
    for (int i=1; i<=M; i++)
    {
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
}
void DFS(int Nod)
{
    Viz[Nod] = true;
    for (unsigned int i=0; i<G[Nod].size(); i++)
    {
        int Vecin = G[Nod][i];
        if (Viz[Vecin] == false)
        {
            DFS(Vecin);
        }
    }
}
int Neviz()
{
    for (int i=1; i<=N; i++)
    {
        if (Viz[i] == false)
            return i;
    }
    return 0;
}
int main()
{
    Read();
    int CC=0;
    for (int i=1; i<=N; i++)
    {
        if (Viz[i] == false)
        {
            CC++;
            DFS(i);
        }
    }
    fout << CC;
    return 0;
}