#include <fstream>
#include <vector>

using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
const int N = 100005;

vector <int> v[N];
int n, m, viz[N];

void dfs(int nod)
{
    viz[nod] = 1;
    vector <int> :: iterator it;
    for(it = v[nod].begin(); it < v[nod].end(); ++it)
        if(viz[*it] == 0)
            dfs(*it);

}

int main()
{
    in >> n >> m;
    int a, b, i;
    for(i = 1; i <= n; i++)
    {
        in >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    int componente = 0;
    for(i = 1; i <= n; i++)
    {
        if(viz[i] == 0)
        {
            componente ++;
            dfs(i);
        }
    }
    out << componente;

    return 0;
}