#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

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


const int nmax=100000;

int n,m;
bool viz[nmax];
vector <int> M[nmax];
int k=0;
void dfs(int Nod)
{
    viz[Nod]=true;
    for(unsigned int i=1;i<=M[Nod].size();i++)
    {
        int Vecin=M[Nod][i];
        if(!viz[Vecin])
            dfs(Vecin);
    }
}
void Citire()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        fin>>x>>y;
        M[x].push_back(y);
        M[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
    {
        if(!viz[i])
        {
            k+=1;
            dfs(i);
        }

    }
}

int main()
{
    Citire();
    fout<<k<<"\n";
    return 0;
}