#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m,insule=0;
const int nlim=100005;
bool viz[nlim];
vector <int> muchii[nlim];
void dfs(int nod)
{
    viz[nod]=1;
    for(int i=0;i<muchii[nod].size();i++)
    {
        if(!viz[muchii[nod][i]])
            dfs(muchii[nod][i]);
    }
}
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(!viz[i])
        {
            insule++;
            dfs(i);
        }
    }
    fout<<insule;
}
int main()
{
    citire();
    return 0;
}