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

using namespace std;

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


const int MAX=100009;

vector <int > D[MAX];

bool Vizitat[MAX]={false};
int n,m,Nr;

void citire ()
{
    f>>n>>m;
    for (int i=1; i<=m; i++)
    {
        int x,y;
        f>>x>>y;
        D[x].push_back(y);
        D[y].push_back(x);

    }
}

void DFS(int i)
{
    Vizitat[i]=true;
    for (unsigned int k=0; k<D[i].size(); k++)
    {
        int Vec=D[i][k];
        if (!Vizitat[Vec])
        {
            DFS(Vec);

        }
    }

}



int main()
{
  citire();
  for (int i=1; i<=n; i++)
        if (!Vizitat[i])
        {
            DFS(i);
            Nr++;
        }
  g<<Nr;
}