# include <fstream>
# include <vector>
using namespace std;
int viz[200005],n,m,x,y,contor=0;

ifstream f("dfs.in");
ofstream g("dfs.out");
vector <int> A[100001];
void citeste_graf()
{
     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);
     }
     f.close();
     
}
void df(int k)
{
     viz [k]=1;
     int nr_vecini,i;
     nr_vecini=A[k].size();
     for (i=0;i<nr_vecini;i++)
     if (viz[A[k][i]]==0)
        df (A[k][i]);
}

int main()
{
    citeste_graf();
    int i;
    for (i=1;i<=n;i++)
      if (viz[i]==0)
            {
             contor++;
             df(i);
             }
    g<<contor;
    g.close();
    return 0;
}