#include <bits/stdc++.h>

void DFS(int k, const std::vector<std::vector<int>>& L, std::vector<int>& viz)
{
    viz[k] = 1;
    for(const auto& w: L[k])
        if(viz[w] == 0) DFS(w, L, viz);
}

int main()
{
    std::ifstream fin("dfs.in");
    std::ofstream fout("dfs.out");
    int N{}, M{}, x, y;
    fin >> N >> M;
    std::vector<std::vector<int>> L(N+1);
    std::vector<int> viz(N+1, 0);
    for(int i = 0; i < M; i++)
    {
        fin >> x >> y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    int nr_conexe = 0;
    for(int i = 0; i < N; i++)
        if(viz[i] == 0)
        {
            DFS(i, L, viz);
            nr_conexe++;
        }
    fout << nr_conexe;
    fin.close();
    fout.close();
    return 0;
}