#include <fstream>
#include <vector>
#include <algorithm>
#define NMAX 100002
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,nrc;
vector <int> G[NMAX];
bool viz[NMAX];//viz[i]=1 daca a fost vizitat ; 0 althel
void citire();
void dfs(int x);
int main()
{int i;
    citire();
    for(i=1;i<=n;i++)
        if(!viz[i]){ dfs(i); nrc++; }
    fout<<nrc<<'\n';
    return 0;
}
void citire()
{int i,j,m,k;
    fin>>n>>m;
    for(k=0;k<m;k++)
    {
        fin>>i>>j;
        G[i].push_back(j);
        G[j].push_back(i);
    }
    /*for(i=1;i<=n;i++)
        sort(G[i].begin(),G[i].end());*/
}
void dfs(int x)
{int i;
    //fout<<x<<' ';
    viz[x]=1;
    //parcurg vecinii vf x
    for(i=0;i<G[x].size();i++)
        if(!viz[G[x][i]])
            dfs(G[x][i]);
}