#include <iostream>
#include <fstream>
#include <vector>
#define dim 100001
using namespace std;
vector <int> L[dim];
bool v[dim];
int i,x,y,n,m,cc;
void dfs (int a)
{
     v[a]=1;
    for(int i=0;i<L[a].size();i++)
        if(v[L[a][i]]==0)
        dfs(L[a][i]);

}
int main()
{
  ifstream fin ("dfs.in");
  ofstream fout ("dfs.out");
  fin>>n>>m;
  for(i=1;i<=m;i++)
  {
      fin>>x>>y;
      L[x].push_back(y);
      L[y].push_back(x);
  }
  for(i=1;i<=n;i++)
  {
      if(v[i]==0)
      {
          cc++;
          dfs(i);
      }
  }
  fout<<cc;
}