#include <fstream>
#include <algorithm>
#include <vector>
#define NMAX 100001
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,nrc;
vector <int> G[NMAX];
bool viz[NMAX]; //vis[i]=1 varful i a fost vizitat, 0 caz contrar
void citire();
void dfs(int x);
int main()
{
    int i;
    citire();
    for(i=1;i<=n;i++)
        if(viz[i]==0)
         {nrc++; dfs(i);}
    fout<<nrc<<'\n';
    return 0;
}
void citire()
      {
       int i,j,m,k;
       fin>>n>>m;
       for(k=0;k<m;k++)
          {
          fin>>i>>j;
          G[i].push_back(j);
          G[j].push_back(i);
          }
        /* for(i=1;i<=n;i++)
           sort(G[i].begin(),G[i].end()); */
      }
void dfs(int x)
        {
         int i;
         //fout<<x<<' ';
         viz[x]=1;
         //parcurg vecinii varfului x
         for(i=0;i<G[x].size();i++)
             if(!viz [G[x][i]])
                dfs(G[x][i]);
        }