#include <cstdio>
#include <vector>

using namespace std;

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

int a,b,nr,viz[101090];
int n,m;
vector<int> v[100208];

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


int main()
{
	int i;
	
	freopen(file_in,"r",stdin);
	freopen(file_out,"w",stdout);
	
	scanf("%d %d", &n, &m);
	
	while(m--)
	{
		scanf("%d %d", &a, &b);
		
		v[a].push_back(b);
		v[b].push_back(a);
	}
	
	
	nr=0;
	
	memset(viz,0,sizeof(viz));
	
	for (i=1;i<=n;++i)
		if (!viz[i])
		{
			nr++;
			dfs(i);
		}
		
		
	printf("%d", nr);

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