/*
        Depth first - parcurgerea in adancime
*/

#include <iostream>
#include <fstream>

using namespace std;

ifstream in("dfs.in");
ofstream out("dfs.out");

int a[50][50],n,s[50];

void in_graf()
{
    int i,j,dump;
    in>>n>>dump;
    while(in>>i>>j) a[i][j]=a[j][i]=1;
    in.close();
 }

void DF(int nod)
{
    int k;
    s[nod]=1;
    for(k=1;k<=n;k++)
	if(a[nod][k]==1 && s[k]==0) DF(k);
}

int main()
{
     int cont = 0;
     in_graf();
     for(int i=1;i<=n;i++)
        if(s[i]==0)
            {
                cont++;
                DF(i);
            }

      cout<<cont;
      return 0;
}