//dfs

#include<stdio.h>
#include<vector>

using namespace std;

#define NMAX 100001
#define input "dfs.in"
#define output "dfs.out"
vector<int> g[NMAX];
int n,m,x,y;
bool viz[NMAX];

void open()
{
	freopen(input,"r",stdin);
	freopen(output,"w",stdout);
}

void read()
{
	scanf("%d%d",&n,&m);
	for(int i=1;i<=m;i++)
	{
		scanf("%d%d",&x,&y);
		g[x].push_back(y);
		g[y].push_back(x);
	}
}

void dfs(int nod)
{
	viz[nod]=true;
	for(int i=0;i<=g[nod].size();i++)
	{
		int current=g[nod][i];
		if(!viz[current])
			dfs(current);
	}
}

void count()
{
	int nr=0;
	for(int i=1;i<=n;i++)
		if(!viz[i])
			{
				nr++;
				dfs(i);
			}
	printf("%d\n",nr);
}

int main()
{
	open();
	read();
	count();
	return 0;
}