#include <fstream>
#define Nmax 100005
using namespace std;

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

struct nod{int x; nod *urm;};

nod *L[Nmax];
nod *p;
int n,m;
int viz[Nmax];

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()
{
    f>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        f>>x>>y;
        adauga(x,y);
        adauga(y,x);
    }
    int k=0;
    for(int i=1;i<=n;i++)
        if(viz[i]==0)
        {
            k++;
            dfs(i);
        }
    g<<k;
    f.close();
    g.close();
    return 0;
}