#include <fstream>
#include <vector>
#define dim 100007
using namespace std;
ifstream fin ("dfs.in");
ofstream fout ("dfs.out");
int cc, n, m, i, j, f[dim];
vector <int> L[dim];
void dfs (int nod)
{
    f[nod]=1;
    for (int i=0; i<L[nod].size(); i++)
    {
        int vecin=L[nod][i];
        if (f[vecin]==0)
            dfs(vecin);
    }
}
int main ()
{
    fin>>n>>m;
    for (int t=1; t<=m; t++)
    {
        fin>>i>>j;
        L[i].push_back(j);
        L[j].push_back(i);
    }
    for (i=1; i<=n; i++)
        if (f[i]==0)
        {
            cc++;
            dfs(i);
        }
    fout<<cc;

}