#include <fstream>
#include <vector>
#define mn 100001

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

 vector<int> graph[mn];
 int n,m,vist[mn];

void dfs(int vert)
{
    vist[vert]=true;

      for (vector<int>::iterator i=graph[vert].begin();i!=graph[vert].end();i++)
      {
            if (!vist[*i])
                     dfs(*i);
      }
}

int main()
{
    fin >> n >> m;
    int a,b;

     for (int i=1;i<=m;i++)
     {
         fin >> a >> b;
         graph[a].push_back(b);
         graph[b].push_back(a);
     }

    int nr=0;

    for (int i=1;i<=n;i++)
      if (!vist[i])
        {
          nr++;
          dfs(i);
        }
    fout << nr << "\n";
    return 0;
}