#include<cstdio>
#include<vector>
using namespace std;
vector<int> v[100001];
void read(),solve(),DFS(int);
int x,y,N,M,i,sol;
bool viz[60000000];
int main()
{
	read();
	solve();
	return 0;
}
void read()
{
	freopen("dfs.in","r",stdin);
	freopen("dfs.out","w",stdout);
	scanf("%d%d",&N,&M);
	for(i=1;i<=M;i++)
	{
		scanf("%d%d",&x,&y);
		v[x].push_back(y);
		v[y].push_back(x);
	}
}
void solve()
{
	for(i=1;i<=N;i++)
	{
		if(viz[i])continue;
		sol++;
		viz[i]=1;
		DFS(i);
	}
	printf("%d",sol);
}
void DFS(int I)
{
	vector<int>::iterator q;
	for(q=v[I].begin();q!=v[I].end();q++)
	{
		if(viz[*q])continue;
		viz[*q]=1;
		DFS(*q);
	}
}