#include<fstream>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
struct nod
{
    int vecin;
    nod *adr;
};
nod *L[100002],*p;
int n,m,viz[100002],x,y,i,c;
void DFS(int vfstart,int viz[], nod *L[])
{
    nod *p;
    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;
    }
    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;
}