#include <bits/stdc++.h>
using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

typedef struct nod
{
    int x;
    nod *a;

}*poznod;

poznod v[100005];
int f[100005]={0};
int n,m;

void adaugare(poznod &dest,int val)
{
    poznod p;
    p=new nod;
    p->x=val;
    p->a=dest;
    dest=p;
}

void citire()
{
    fin>>n>>m;
    int x,y;
    for (int i=1;i<=m;i++)
    {
        fin>>x>>y;
        adaugare(v[x],y);
        adaugare(v[y],x);
    }
}

void DFS(int nod)
{
    poznod p;
    f[nod]=1;
    for (p=v[nod];p!=NULL;p=p->a)
    {
        if (!f[p->x]){
                DFS(p->x);
        }
    }
}


int main()
{
    citire();
    int ans=0;
    for (int i=1;i<=n;i++)
    {
        if(f[i]==0)
        {
            ans++;
            DFS(i);
        }
    }
    fout<<ans;
}