#include<fstream>
#include<vector>
#define maxn 100010

using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");

vector<int> a[maxn];
bool viz[maxn];
int n,m,k;
void read()
{
	in>>n>>m;
	int x,y;
	for(int i=1;i<=m;i++)
	{
		in>>x>>y;
		a[x].push_back(y);
		a[y].push_back(x);
	}
}

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

int main()
{
	read();
	for(int i=1;i<=n;i++)
		if(viz[i]==0) k++,dfs(i);
}