# include <fstream>
# include <vector>
# define Nmax 100002
using namespace std;
ifstream f("dfs.in"); ofstream g("dfs.out");
vector<int> a[Nmax];
int n,m,x,y,nr,viz[Nmax];
void dfs(int p)
{int q;
 viz[p]=1;
 for(unsigned int i=0; i<a[p].size(); ++i ) 
	 {q=a[p][i];
	  if(!viz[q]) dfs(q);
	 }
}
int main()
{
 f>>n>>m;
 for(int i = 1; i <= m; ++i) {f>>x>>y; a[x].push_back(y); a[y].push_back(x);}
 for(int i=1; i<=n; ++i ) 
	 {if(!viz[i]) 
		  {nr++; dfs(i);}
	 }
 g<<nr<<'\n'; g.close(); return 0;
}