#include <fstream>
#include <queue>
#include <vector>
#define N 100001

using namespace std;

vector <int> G[N];
int n,m;
int viz[N],nrcomp;

void Citire()
{
    ifstream fin("dfs.in");
    int x,y;
    fin>>n>>m;
    while (m--)
    {
        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    fin.close();
}

void Dfs(int nod)
{
    int i;
    viz[nod]=1;
    for (i=0;i<G[nod].size();++i)
        if (!viz[G[nod][i]])
            Dfs(G[nod][i]);
}

void Afisare()
{
    ofstream fout("dfs.out");
    int i;
    for (i=1;i<=n;i++)
    if (!viz[i])
    {
        Dfs(i);
        nrcomp++;
    }

    fout<<nrcomp;

    fout.close();
}
int main()
{
    Citire();
    Afisare();
    return 0;
}