#include <fstream>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

struct nod {int info; nod *urm;};
nod *p, *vecini[100001];
int n,m,cnt;
bool viz[100001];

void add(nod *&dest, int val)
{
    p=new nod;
    p->info=val;
    p->urm=dest;
    dest=p;
}

void citire()
{
    int x,y;
    fin>>n>>m;
    for (int i=1; i<=m; ++i)
    {
        fin>>x>>y;
        add(vecini[x],y);
        add(vecini[y],x);
    }
}

void DFS(int nrNod)
{
    viz[nrNod]=true;
    for (nod *i=vecini[nrNod]; i; i=i->urm)
        if (!viz[i->info]) DFS(i->info);
}

int main()
{
    citire();
    for (int i=1; i<=n; ++i)
        if (!viz[i]) {
            ++cnt;
            DFS(i);
        }
    fout<<cnt;
    return 0;
}