#include <iostream>
#include <fstream>
#define nmax 100005
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m,viz[nmax],cnt=0;

typedef struct nod
{
    int val;
    nod*urm;
}*p;
p pnod[nmax];
void adauga(int x, nod*&pp)
{
    p q;
    q=new nod;
    q->val=x;
    q->urm=pp;
    pp=q;

}
void citire()
{

    fin>>n>>m;
    int i,x,y;
    for(int i =1 ; i <= m ; i++)
    {
        fin>>x>>y;
        adauga(y,pnod[x]);
        adauga(x,pnod[y]);
    }

}
void dfs(int node)
{
    p w;
    viz[node]=1;
    for(w=pnod[node]; w!=NULL; w=w->urm)
    {
        if(!viz[w->val]) dfs(w->val);
    }


}
int main()
{
    citire();
    for(int i =1; i <= n ; i ++)
        if(!viz[i])
        {
            cnt++;
            dfs(i);
        }
    fout<<cnt;
    return 0;
}