#include<fstream>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
struct nod
{
    int vecin;
    nod *adr;
};
int M,N,x,y,i,viz[100002];
nod *L[100002],*p;
void DFS(int vfstart,int viz[],nod *L[])
{
    nod *p;
    ///fout<<vfstart<<" ";
    viz[vfstart]=1;
    for(p=L[vfstart];p!=0;p=p->adr)
    {
        if(viz[p->vecin]==0)
        {
            DFS(p->vecin,viz,L);
        }
    }
}

int main ()
{
    fin>>N>>M;
    for(i=1;i<=M;i++)
    {
        fin>>x>>y;
        p=new nod;
        p->vecin=y;
        p->adr=L[x];
        L[x]=p;
        p=new nod;
        p->vecin=x;
        p->adr=L[y];
        L[y]=p;
    }
    int c=0;
    for(i=1;i<=N;i++)
    {
        if(viz[i]==0)
        {
            c++;
            DFS(i,viz,L);
        }
    }
    fout<<c;
    fin.close();
    fout.close();
    return 0;
}