# include <fstream>
# include <vector>

using namespace std;

vector <int> a[200005];

int viz[200005], m, n, i, x, y, ct;

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

void dfs(int nod)
{
     vector <int>:: iterator it;
     viz[nod] = 1;
     for (it = a[nod].begin(); it != a[nod].end(); it++)
         if (!viz[*it]) 
         {
                        viz[*it] = 1; dfs(*it);
                        } 
}         

int main()
{
    
    f >> n >> m;
    for (i = 1; i <= m; i++)
    {
        f >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
        }
        
    for (i = 1; i <= n; i++)
        if (!viz[i]) 
        {
                     ct++;
                     dfs(i);
                     }
                     
        g << ct;
        
return 0;
}