#include <fstream>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
bool viz[100001];
struct nod
{
    int inf;
    struct nod *urm;
} *v[100001];
void adauga(int a,int b)
{
    nod *p=new nod;
    p->inf=b;
    p->urm=v[a];
    v[a]=p;
}
void dfs(int x)
{
    viz[x]=1;
    for(nod *step=v[x];step!=0;step=step->urm)
    {
        if(viz[step->inf]==0) dfs(step->inf);
    }
}
int main()
{
    int n,m,a,b,i,nr=0;
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>a>>b;
        adauga(a,b);
        adauga(b,a);
    }
    for(i=1;i<=n;i++)
    {
        if(viz[i]==0)
        {
            nr++;
            dfs(i);
        }
    }
    fout<<nr;
}