#include<fstream>
#include<vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n,m,i,con,x,y;
vector<int>a[100005];
bool viz[100005];
void dfs(int nod)
{
    for(i=0;i<a[nod].size();i++)
      if(viz[a[nod][i]]==0)
      {
          viz[a[nod][i]]=1;
          dfs(a[nod][i]);
      }
    viz[nod]=1;
}
int main()
{
    f>>n>>m;
    for(i=1;i<=m;i++)
    {
        f>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for(i=1;i<=n;i++)
      if(viz[i]==0)
      {
          dfs(i);
          con++;
      }
    g<<con;
    return 0;
}