#include <fstream>
#include <vector>
using namespace std;
ifstream fin ("dfs.in");
ofstream fout ("dfs.out");
int n,m,x,y,i,v[100010],cc,j;
vector <int> L[100010];
void dfs (int nod) {
    v[nod]=1;
    for(int i=0;i<L[nod].size();i++){
        int vecin =L[nod][i];
        if(v[vecin]==0)
            dfs(vecin);
    }
  }
int main(){
   fin>>n>>m;
   for(i=1;i<=m;i++){
    fin>>x>>y;
    L[x].push_back(y);
    L[y].push_back(x);
   }
   for(i=1;i<=n;i++)
   if(v[i]==0){
    cc++;
    dfs(i);
   }

   fout<<cc;
return 0;
}