#include <fstream>
#include <vector>

#define NMAX 100009

std::vector<int> Adiacenta[NMAX];  // liste de adiacenta
bool vizitat[NMAX];

void Dfs(int curent)
{
    vizitat[curent] = true;
    for (auto it = Adiacenta[curent].begin(); it != Adiacenta[curent].end(); ++it)
        if (!vizitat[*it])
            Dfs(*it);
}

int main()
{
    std::ifstream f("dfs.in");
    std::ofstream g("dfs.out");
    int N, M;

    f >> N >> M;
    for (int x, y, i = 0; i < M; ++i)
    {
        f >> x >> y;
        Adiacenta[x].push_back(y);
        Adiacenta[y].push_back(x);
    }

    int nrComp = 0;
    for (int i = 1; i <= N; ++i)
        if (!vizitat[i])
        {
            ++nrComp;
            Dfs(i);
        }

    g << nrComp;

    return 0;
}