#include <fstream>
#include <vector>
#define pb push_back

using namespace std;

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

int n, m, x, y, sol=0;
short viz[100005];
vector < int > a[100005];

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

int main()
{
    f>>n>>m;
    for (int i=1; i<=m; i++)
    {
        f>>x>>y;
        a[x].pb(y); a[y].pb(x);
    }

    for (int i=1; i<=n; i++)
      if (viz[i]==0)
      {
          dfs(i); ++sol;
      }

    g<<sol<<'\n';
    f.close(); g.close();
    return 0;
}