#include<fstream>
#include<vector>
#define NMAX 100010

using namespace std;

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

vector<int> a[NMAX];
int n, m, vz[NMAX];

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

void DFS(int nod)
{
    int i;

    vz[nod]=1;

    for (i=0; i<a[nod].size(); ++i)
        if (!vz[a[nod][i]]) DFS(a[nod][i]);
}

void Solve()
{
    int i, nr=0;

    for (i=1; i<=n; ++i)
        if (!vz[i])
        {
            DFS(i);
            ++nr;
        }
    g<<nr<<"\n";
}

int main()
{
    Citeste();
    Solve();
    f.close();
    g.close();
    return 0;
}