#include <fstream>
#include <vector>
using namespace std;
ifstream fin ("dfs.in");
ofstream fout ("dfs.out");
vector <int> lista[100001];
int v[100001];
void dfs (int nod)
{
    int i;
    v[nod]=1;
    for (i=0;i<lista[nod].size();i++)
        if (v[lista[nod][i]]==0)
            dfs(lista[nod][i]);
}
int main ()
{
    int nr=0,n,m,i,x,y;
    fin>>n>>m;
    for (i=1;i<=m;i++)
    {
        fin>>x>>y;
        lista[x].push_back(y);
        lista[y].push_back(x);
    }
    for (i=1;i<=n;i++)
        if (v[i]==0)
        {
            nr++;
            dfs(i);
        }
    fout<<nr;
    return 0;
}