#include <fstream>
#include <vector>
#define NMAX 100000
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n;
vector< int >v[NMAX];
vector<bool> viz(NMAX,false);
void dfs(int x)
{
    viz[x]=true;
    for(unsigned i=0;i<v[x].size();i++){int Vecin=v[x][i];
        if(!viz[Vecin]) dfs(Vecin);}
}
int main()
{
   int m,x,y,nrc=0;
   fin>>n>>m;
   for(unsigned i=0;i<m;i++)
   {
       fin>>x>>y;
       v[x].push_back(y);
       v[y].push_back(x);}
       for(unsigned i=1;i<=n;i++)
        if(!viz[i])
       {

           dfs(i);
           ++nrc;

       }

fout<<nrc;
   fin.close();
   fout.close();
       return 0;
}