#include <fstream>

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int nr=0,vf[400001],lst[100001],urm[400001];
bool viz[100001];
void adauga (int x,int y){
    nr++;
    vf[nr]=y;
    urm[nr]=lst[x];
    lst[x]=nr;
}
void dfs (int x){
    viz[x]=true;
    int p,y;
    p=lst[x];
    while (p!=0){
       y=vf[p];
       if(!viz[y])
        dfs(y);
       p=urm[p];
    }
}
int main()
{   int x,y,i,n,m,nc=0;
    f>>n>>m;
    for(i=1;i<=m;i++)
    {
      f>>x>>y;
      adauga(x,y);
      adauga(y,x);
    }
    for(i=1;i<=n;i++)
        if(!viz[i]){
            nc++;
            dfs(i);
        }
    g<<nc;
}