#include <iostream>
#include<fstream>
#include<vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int N,M;
const int NLIM = 100005;
bool vizitat[NLIM];
vector <int> Muchii[NLIM];


int insule=0;

void DFS(int Nod)
{
    vizitat[Nod] = true;
    for(unsigned int i=0; i<Muchii[Nod].size();i++)
    {
        int Vecin = Muchii[Nod][i];
        if(!vizitat[Vecin])
            DFS(Vecin);
    }
}
void Citire()
{
    fin>>N>>M;
    for( int i=1;i<=M;i++)
    {
        int x,y;
        fin>>x>>y;
Muchii[x].push_back(y);
Muchii[y].push_back(x);
    }
    for(int i=1;i<=N;i++)
    {
if(!vizitat[i])
{insule+=1; DFS(i);
    }
}
}
int main()
{ Citire();
fout<<insule<<"\n";
    return 0;
}