#include <fstream>
#include <vector>

using namespace std;

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

int n, m;
bool used[100005];
vector < int > a[100005];

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

void Dfs (int nod)
{
   used[nod] = 1;
   int lg = a[nod].size();
     for (int j=0; j<lg; j++)
     {
         if (!used[a[nod][j]])
         {
             Dfs(a[nod][j]);
         }
     }
}

void Solve ()
{
   int sol = 0;
    for (int i=1; i<=n; i++)
    {
        if (!used[i])
        {
            sol ++;
            Dfs(i);
        }
    }
   g << sol;
}

int main()
{
  Read();
  Solve();
    return 0;
}