#include <fstream>

using namespace std;

ifstream f("in.txt");
ofstream g("in.txt");
struct point{
        int inf;
        point *leg;
};
point *l[100000],*p;
bool sel[100000];
int nr,n,m,x,y,i;
void dfs (int x)
{
point *poz;
sel[x]=true;
poz=new point;
poz=l[x];
while (poz)
{
    if (!sel[poz->inf])
        dfs(poz->inf);
    poz=poz->leg;
}
}
int main()
{
   point *prim;
   prim=new point;
   f>>n>>m;
   for(i=1;i<=n;i++)
   {
       p=new point;
       p->inf=y;
       p->leg=l[x];
       l[x]=p;
       p=new point;
       p->inf=x;
       p->leg=l[y];
       l[y]=p;

   }
   for(i=1;i<=n;i++)
    if(!sel[i])
    {
        dfs(i);
        nr++;
    }
    g<<nr<<"\n";
    return 0;
}