#include <iostream>
#include <fstream>

using namespace std;

ofstream fout("dfs.out");

int n, m, viz[100005], cnt;

typedef struct nod
{
    int x;
    nod *a;
} *NOD;
NOD v[100005];

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

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

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

int main()
{
    citire();
    int i, cnt=0;
    for(i=1;i<=n;i++){
        if(!viz[i]){
            cnt++;
            DFS(i);
        }
    }
    fout<<cnt<<'\n';
}