#include <fstream>
#include <vector>
#define NMAX 100001
using namespace std;
ifstream cin ("dfs.in");
ofstream cout ("dfs.out");
int n,m,x,y;

vector<int>a[NMAX]; ///am declarat u vector cu NMAX elemente de tip vector din stl
int viz[NMAX];
int nrc=0;
void citire()
{
    cin>>n>>m;
    for (int i=1;i<=m;i++)
    {
        cin>>x>>y;
        ///adaug pe y in lista de adiacenta a lui x
        a[x].push_back(y);
        ///adaug pe x in lista de adiacenta a lui y
        a[y].push_back(x);

    }
}

void afisare()
{
    for (int i=1;i<=n;i++)
    {
        for (int j=0;j<a[i].size();j++)
            cout<<a[i][j]<<' ';
        cout<<endl;
    }
}

void dfs(int nod)
{
    viz[nod]=1;
    for (int i=0;i<a[nod].size();i++)
    {
        int vecin=a[nod][i];
        if (viz[vecin]==0)
        {
            dfs(vecin);
        }
    }
}

int main()
{
    citire();
    for (int i=1;i<=n;i++)
    {
        if (viz[i]==0)
        {
            dfs(i);
            nrc++;
        }
    }
    cout<<nrc;
    return 0;
}