#include <cstdio>
#include <vector>

using namespace std;

#define file_in "dfs.in"
#define file_out "dfs.out"

#define Nmax 101001

int n,m,nr,viz[Nmax];
vector<int> G[Nmax];

void dfs(int nod)
{
	if (viz[nod])
		return ;
	
	viz[nod]=1;
	
	for (int i=0;i<G[nod].size();++i)
		 if (!viz[G[nod][i]])
			 dfs(G[nod][i]);
}


int main()
{
	int i,a,b;
	freopen(file_in,"r",stdin);
	freopen(file_out,"w",stdout);
	
	scanf("%d %d", &n, &m);
	while(m--)
	{
		scanf("%d %d", &a, &b);
		
		G[a].push_back(b);
		G[b].push_back(a);
	}
	
	for (i=1;i<=n;++i)
	     if (!viz[i])
		 {
			 nr++;
			 dfs(i);
		 }
		 
		 
	printf("%d\n", nr);

	fclose(stdin);
	fclose(stdout);
	
	return 0;
	
}