#include <fstream>
#include <vector>
using namespace std;
ifstream fin ("dfs.in");
ofstream fout ("dfs.out");
int n,i,x,y,nr,m,viz[100005];
vector <int> v[100005];
void dfs (int nod)
{
    viz[nod]=1;
    for (int i=0; i<v[nod].size (); i++)
    {
        int vecin=v[nod][i];
        if (viz[vecin]==0)
            dfs (vecin);
    }
}
int main()
{
    fin>>n>>m;
    for (i=1; i<=m; i++)
    {
        fin>>x>>y;
        v[x].push_back (y);
        v[y].push_back (x);
    }
    for (i=1; i<=n; i++)
    {
        if (viz[i]==0)
        {
            nr++;
            dfs (i);
        }
    }
    fout<<nr;
    return 0;
}