#include <fstream>
#include <vector>

const int NMAX = 100005;

using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

int N,M,answer,x,y;
vector <int> v[NMAX];
bool viz[NMAX];

void DFS(int nod)
{
    viz[nod] = true;

    for (int i = 0; i < v[nod].size(); ++i)
    {
        int vecin = v[nod][i];
        if (!viz[vecin])
            DFS(vecin);
    }
}

int main()
{
    f >> N >> M;
    for (int i = 1; i <= M; ++i)
    {
        f >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for (int i = 1; i <= N; ++i)
    {
        if (!viz[i])
        {
            answer++;
            DFS(i);
        }
    }

    g << answer;

    f.close();
    g.close();

    return 0;
}