#include <iostream>
#include <fstream>
#include <vector>
#define NMAX 102
using namespace std;
ifstream fin ("dfs.in");
ofstream fout ("dfs.out");
int n,m,start,nrc;
vector<int> G[NMAX];
int uz[NMAX]; ///pun 1 daca vizitez
void citire ();
void dfs (int x);
void afisare();
int main()
{
    int i;
    citire ();
    for(i=1; i<=n; i++)
        if(!uz[i]) ///am identificat o noua comp conex
        {
            nrc++;
            dfs(i);
        }
     afisare();
    /*for(i=1; i<=n; i++)
        if(uz[i]==0)
        {
         fout<<"NU";
         ok=1;
         break;
        }
    if(ok==0)
        fout<<"DA";
    return 0;*/
}
void citire ()
{
    int x,y;
    fin>>n;
    while (fin>>x>>y)
    {
        G[y].push_back(x);
        G[x].push_back(y);
        //G[x][y]=1;
        //G[y][x]=1;
    }

}
void dfs (int x)
{
    int i;
    ///parcurg graful incepand din vf x
    //fout<<x<<" ";///vizitez pe x
    uz[x]=nrc;///il marchez pe x ca vizitat
    ///parcurg toti vec lui x in ordine crescatoare
    for(i=0; i<G[x].size(); i++)
        if(!uz[G[x][i]])
            dfs(G[x][i]);

}
void afisare()
{
    int i,j;
    fout<<nrc<<'\n';
    /*for(i=1; i<=nrc; i++)
    {
        ///afisez  vf care sunt in comp conexa cu nr i
        for(j=1; j<=n; j++)
            if(uz[j]==i)
                fout<<j<<' ';
        fout<<'\n';
    }*/
}