#include<fstream>
#define nmax 100002
#include<vector>
using namespace std;
fstream f("dfs.in",ios::in);
fstream h("dfs.out",ios::out);
vector<int> g[nmax];
int n,m,i,viz[nmax],comp,x,y;
void DF(int k)
{
    int i,v;
    viz[k]=1;
     for(i=0;i<g[k].size();i++){
         v=g[k][i];
         if(!viz[v]) DF(v);
    }
}
int main()
{
   f>>n>>m;
   while(m>0){
        f>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
        m--;
  }
  for(i=1;i<=n;i++)
    {
        if(viz[i]==0){
              DF(i);
             comp++;
             }

     }
    h<<comp;
    f.close();
    h.close();
  return 0;
}