#include<fstream>
#include<algorithm>
#include<vector>
#define pb push_back
#define dim 100002
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector<int> a[dim];
int n,m,sol;
int viz[dim];
void dfs(int x)
{
	int lg,i;
	viz[x]=1;
	lg=a[x].size();
	for(i=0;i<lg;i++)
		if(viz[a[x][i]]==0)
			dfs(a[x][i]);
}
void rezolva()
{
	int i;
	for(i=1;i<=n;i++)
		if(viz[i]==0)
		{
			sol++;
			dfs(i);
		}
		g<<sol;
}
void citire()
{
	int i,x,y;
	f>>n>>m;
	for(i=1;i<=m;i++)
	{
		f>>x>>y;
		a[x].pb(y);
		a[y].pb(x);
	}
}
int main()
{
	citire();
	rezolva();
	return 0;
}