#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> v[100001];
int n,m,x,y,nr,i,q[100002],viz[100002];
void coada(int x){
      int l,i,p,u;
      p=u=1;
      q[p]=x;
      viz[x]=1;
      while(p<=u){
            l=q[p];
            p++;
            for(i=0;i<v[l].size();i++)
            if(viz[v[l][i]]==0){
               viz[v[l][i]]=1;
               u++;
               q[u]=v[l][i];
            }
      }
}
int main()
{fin>>n>>m;
for(i=1;i<=m;i++){
    fin>>x>>y;
    v[x].push_back(y);
    v[y].push_back(x);

}
 for(i=1;i<=n;i++)
 if(viz[i]==0){
    nr++;
    coada(i);
 }
 fout<<nr;
    return 0;
}