#include <iostream>
#include<fstream>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int viz[100005],i,n,m,x,y,cnt;
struct nod
{
    int x;
    nod *leg;
};
nod *v[100005];
void adauga(nod *&urm,int info)
{
    nod *p;
    p=new nod;
    p->x=info;
    p->leg=urm;
    urm=p;
}
void DFS(int n)
{
    viz[n]=1;
    nod *p;
    for(p=v[n];p!=NULL;p=p->leg)
        if(!viz[p->x])
        DFS(p->x);
}
int main()
{
    f>>n>>m;
    for(i=1;i<=m;i++)
    {
        f>>x>>y;
        adauga(v[x],y);
        adauga(v[y],x);
    }
    for(i=1;i<=n;i++)
    if(!viz[i])
    {
        cnt++;
        DFS(i);
    }
    g<<cnt;
}