#include<iostream>
#include<fstream>
#include<vector>
using namespace std;
#define foreach(v)  for(typeof (v).begin() it=(v).begin();it!=(v).end();it++)
vector <int> G[100005];
int K,viz[100005],M,N;
void dfs(int nod)
{   viz[nod]=1;
    foreach(G[nod])
    if(viz[*it]==0)
     dfs(*it);
}



int main()
{int i,x,y;
        ifstream fin("dfs.in");
fin>>N>>M;
for(i=1;i<=M;i++)
   {fin>>x>>y;
   G[x].push_back(y);
   G[y].push_back(x);
   }
fin.close();
    for(i=1;i<=N;i++)
      if(viz[i]==0)
      {dfs(i);
      K++;}
ofstream fout("dfs.out");

      fout<<K;
fout.close();
      return 0;
}