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

ifstream fin("dfs.in");
ofstream fout("dfs.out");
const int NLIM = 100005;
int N, M, cnt=0;
bool viz[NLIM];
vector < int > Muchii[NLIM];

void DFS(int Nod)
{
    viz[Nod] = true;
    for(unsigned int i = 0; i < Muchii[Nod].size(); i++)
    {
         int Vecin = Muchii[Nod][i];
         if(!viz[Vecin])
            DFS(Vecin);
    }
}
void Citire()
{
    fin >> N >> M;
    for(int i = 1; i <= M; ++i)
    {
        int x, y;
        fin >> x >> y;
        Muchii[x].push_back(y);
        Muchii[y].push_back(x);
    }
    for(int i = 1; i <= N; i++)
    {
        if(!viz[i])
        {
            cnt++;
            DFS(i);
        }
    }

}
int main()
{
    Citire();
    fout << cnt << endl;
    return 0;
}