#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream f ("dfs.in");
ofstream g ("dfs.out");
int verif [100001];
vector <int> muchii[100001];
class graf{
private:
    int n, m, x, y;
public:
    graf(){}
    graf (int n, int m)
    {
        this-> n = n;
        this-> m = m;

        for(int i=1; i<=m; i++){
            f>>x>>y;
            muchii[x].push_back(y);
            muchii[y].push_back(x);
        }
    }
    void dfs(int nod){
        verif[nod]=true;
        for (int i=0; i<muchii[nod].size(); i++){
            int vecin = muchii[nod][i];
            if(verif[vecin]!=true)
                dfs(vecin);
        }
    }
virtual ~graf(){}
};
int main()
{
    int n, m, counter=0;
    f>>n>>m;
    graf g1(n,m);
    for (int i=1;i<=n;i++){
        if (verif[i]!=true){
            counter++;
            g1.dfs(i);
        }
    }
g<<counter;
    return 0;
}