#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
vector <int> vecini[100010];
bool vazut[100010];
void parcurgere(int nod)
{
    vazut[nod]=true;

    for(auto i:vecini[nod])
    {
        if(!vazut[i])
        {
            parcurgere(i);
        }
    }

}
int n,m,suma,a,b;
int main()
{///citim lista de adiacenta, bagam cu push_back()
    in>>n>>m;
    for(int i=1;i<=m;++i)
    {
        in>>a>>b;
        vecini[a].push_back(b);
        vecini[b].push_back(a);
    }
    for(int i=1;i<=n;++i)
    {
        if(!vazut[i])
        {
            parcurgere(i);
            ++suma;
        }
    }

out<<suma;
in.close();
out.close();
    return 0;
}