#include<stdio.h>
#include<vector>
using namespace std;
int n,m,nr,viz[100005];
vector<int> v[100005];

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

int main()
{
	freopen("dfs.in","r",stdin);
	freopen("dfs.out","w",stdout);
	scanf("%d%d",&n,&m);
	int i,x,y;
	for(i=1;i<=m;i++)
	{
		scanf("%d%d",&x,&y);
		v[x].push_back(y);
		v[y].push_back(x);
	}
	for(i=1;i<=n;i++)
		if(!viz[i])
		{
			nr++;
			dfs(i);
		}
	printf("%d\n",nr);
	return 0;
}