#include <fstream>
#define N 100000

using namespace std;

bool viz[N+5];
struct nod
{
    int x;
    nod *urm;
};
nod *L[N+5];
nod *p;
int n,m;
void adauga(int i,int j)
{
    nod *p;
    p=new nod;
    p->x=j;
    p->urm=L[i];
    L[i]=p;
}
void dfs(int j)
{
    nod *p;
    viz[j]=1;
    p=L[j];
    while(p)
    {
        if(viz[p->x]==0)
            dfs(p->x);
        p=p->urm;
    }
}
int main()
{
    ifstream f("dfs.in");
    ofstream g("dfs.out");
    f>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        f>>x>>y;
        adauga(x,y);
        adauga(y,x);
    }
    int nr=0;
    for(int i=1;i<=n;i++)
        if(viz[i]==0)
        {
            nr++;
            dfs(i);
        }
    g<<nr;
    return 0;
}