#include <iostream>
#include <fstream>

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

#define Nmax 100005
struct elem{
int inf;
elem *adr;
}*v[Nmax];
int n,m,viz[Nmax];
void citesc()
{
    int x,y;
    elem *p;
    f>>n>>m;
    for(int i=1;i<=m;i++)
    {
        f>>x>>y;
        p=new elem;
        p->inf=y;
        p->adr=v[x];
        v[x]=p;
        p=new elem;
        p->inf=x;
        p->adr=v[y];
        v[y]=p;

    }
}

void dfs(int x){
    viz[x]=1;
    for(elem *p=v[x];p!=NULL;p=p->adr)
    if(viz[p->inf]==0)
        dfs(p->inf);
}
/*void afis()
{
    for(int i=1;i<=n;i++)
        {
            for(elem *p=v[i];p!=NULL;p=p->adr)
                cout<<p->inf<<' ';
            cout<<'\n';
        }
}*/
int main()
{
    citesc();
    int nrc=0;
    for(int i=1;i<=n;i++)
        if(viz[i]==0){
            nrc++;
            dfs(i);
        }
    g<<nrc;
    return 0;
}