#include <cstdio>
#include <algorithm>
#include <vector>

using namespace std;

#define Nmax 100100
#define FIN "dfs.in"
#define FOUT "dfs.out"
#define pb push_back
#define sz size


vector<int> a[Nmax];
int n,m;
int viz[Nmax];
int x,y,nr;

inline void dfs(int nod)
{
	int i,j;
	viz[nod]=1;
	for (i=1;i<=a[nod].sz();++i)
		 if (!viz[a[nod][i]])
			  dfs(a[nod][i]);
} 

inline void citire()
{
	int i,j;
	
	freopen(FIN,"r",stdin);
	freopen(FOUT,"w",stdout);
	
	scanf("%d %d\n", &n,&m);
	for (i=1;i<=m;++i)
	{
		scanf("%d %d\n", &x,&y);
		a[x].pb(y);
		a[y].pb(x);
	}
	for(i=1;i<=n;++i)
		 if (!viz[i])
		 {
			 nr++;
			 dfs(i);
		 }
}

inline void scrie()
{
	int i,j;
	printf("%d\n", nr);
}


int main()
{
	citire();
	scrie();
	
	fclose(stdin);
	fclose(stdout);
	
	return 0;
}