#include<bits/stdc++.h>
using namespace std;
ifstream f("dfs.in"); ofstream g("dfs.out");
int n,m,a[10001][10001],viz[10001],nrcomp;
void DFS(int x)
{ 	int i;
  	viz[x]=nrcomp;
  	for(i=1;i<=n;i++)
    	if (a[x][i]==1 && viz[i]==0) DFS(i);
}
int main()
{	f>>n;
 	int x,y;
 	while(f>>x>>y)
    {	a[x][y]=1; a[y][x]=1; }
 	for(int i=1;i<=n;i++)
    	if (viz[i]==0) { nrcomp++; DFS(i);}
 	g<<nrcomp;
 	g.close(); return 0;
}