#include <fstream>
#include <vector>
using namespace std;

ifstream f("dfs.in ");
ofstream g("dfs.out ");

int use[10001];
vector<int> G[10001];

void DFS(int nod){
    vector <int> :: iterator it;
    use[nod]=1;
    for(it=G[nod].begin();it!=G[nod].end();it++)
    {
        if(!use[*it])
            DFS(*it);
    }
 
}

int main(){
	int n, m;
	f>>n>>m;
	for(int i = 1; i <= n; i++){
		int x,y;
		f>>x>>y;
		G[x].push_back(y);
		G[y].push_back(x);
	}
	int k=0;
    for(int i=1;i<=n;i++)
    {
        if(!use[i])
        {
               k++;
               DFS(i);
 
        }
    }
	g<<k;
}