#include <fstream>
#include <vector>
#define NMAX 100002
std::ifstream f ("dfs.in");
std::ofstream g ("dfs.out");
using namespace std;
int n, m, nrConexe;
bool viz[NMAX];
vector<int>graf[NMAX];

void read ();
void DFS (int nod);

int main()
{
    read();
    for (int i=1;i<=n;++i)
    {
        if (viz[i] == false)
        {
            ++nrConexe;
            DFS(i);
        }
    }
    g<<nrConexe;
    return 0;
}

void read ()
{
    f>>n>>m;
    for (int i=1;i<=m;++i)
    {
        int x, y;
        f>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
}

void DFS (int nod)
{
    viz[nod] = true;
    int nrVecini = graf[nod].size();
    for (int i=0;i<nrVecini;++i)
    {
        int  nextNode = graf[nod][i];
        if (viz[nextNode] == false)
            DFS(nextNode);
    }
}