#include <cstdio>
#include <vector>
#include <fstream>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> victor[100002];
int viz[100001],k,x,y,m,n,i;


void DFS(int q)
{ int i;
     viz[q]=1;
     for(i=0; i<victor[q].size(); ++i)
          if(!viz[victor[q][i]])
          DFS(victor[q][i]);


}


int main()
{   fin>>n>>m;

    for(i=1;i<=m;i++)
      {
        fin>>x>>y;
        victor[x].push_back(y);
        victor[y].push_back(x);
      }
   for(i=1; i<=n; ++i)
       if(!viz[i])
        {k++;
        DFS(i);
        }
   fout<<k;
   return 0;
}