#include <fstream>
#include<bitset>
using namespace std;
ifstream f ("dfs.in");
ofstream g("dfs.out");
int n,a[100][100],c;
bitset<100000> viz;
void df(int nod)
{
    viz[nod]=1;
    for(int i=1;i<=n;++i)
        if(viz[i]==0 && a[nod][i]==1)
        df(i);
}
int main()
{
    int x,y;
    f>>n;
    while(f>>x>>y)
        a[x][y]=a[y][x]=1;
         for(int i=1;i<=n;++i)
        if(viz[i]==0)
    {
    df(i);
    c++;
    }
    g<<c;
    return 0;
}