#include<cstdio>
#include<vector>
#define N 100001
using namespace std;
vector<int>a[N];
int n,m,x,y,nr;
bool viz[N];

void DFS(int x)
{
	viz[x]=true;
	for(int i=0;i<(int)a[x].size();i++)
	{
		if(!viz[a[x][i]])
			DFS(a[x][i]);
	}
}
void citire()
{
	freopen("dfs.in","r",stdin);
	freopen("dfs.out","w",stdout);
	scanf("%d%d",&n,&m);
	for(int i=1;i<=m;i++)
	{
		scanf("%d%d",&x,&y);
		a[x].push_back(y);
		a[y].push_back(x);
	}
}
void parcurgere()
{
	for (int i=1;i<=n;i++)
		if(!viz[i])
		{
			nr++;
			DFS(i);
		}
}

int main()
{
	citire();
	parcurgere();
	printf("%d\n",nr);
	return 0;
}