#include <fstream>
#include <vector>

#define Nmax 100002

using namespace std;

ifstream fin ("dfs.in");
ofstream fout ("dfs.out");

int n, m, i, j, viz[Nmax], k;
vector <int> G[Nmax];

inline void DFS (int nod, int k)
{
    vector <int> :: iterator it;

    viz[nod] = k;
    for (it = G[nod].begin(); it != G[nod].end(); it ++)
    {
        if (viz[*it] == 0)
        {
            DFS(*it, k);
        }
    }

}

int main()
{
    fin >> n >> m;
    while (fin >> i >> j)
    {
        G[i].push_back(j);
        G[j].push_back(i);
    }
    for (i = 1; i <= n; i ++)
    {
        if (viz[i] == 0)
        {
            k ++;
            DFS(i, k);
        }
    }

    fout << k;


    fin.close();
    fout.close();
    return 0;
}