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

ifstream cin("dfs.in");
ofstream cout("dfs.out");

const int NLIM = 100005;
vector<int> Muchii[NLIM];
bool Vizitat[NLIM];
int n, m,cnt;

void dfs(int Nod){
    Vizitat[Nod] = true;
    for (unsigned int i = 0; i < Muchii[Nod].size(); i++){
        int Vecin = Muchii[Nod][i];
        if (!Vizitat[Vecin])
            dfs(Vecin);
    }
}

int main()
{
    cin >> n >> m;
    for (int i = 1; i <= m;i++){
        int x, y;
        cin >> x >> y;
        Muchii[x].push_back(y);
        Muchii[y].push_back(x);
    }
    for (int i = 1; i <= n;i++)
        if(!Vizitat[i])
            dfs(i), cnt++;
    cout<<cnt;
}