#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
#define Nmax 100000
 
using namespace std;
 
int  n,m ;
 
vector < vector<int> > v1(Nmax);
 
vector< bool > viz(Nmax,false);
 
void citire()
{
    ifstream in("dfs.in");
 
    in>>n>>m ;
 
    int x, y;
 
    for(int i = 0 ; i <  m ; i ++)
    {
        in>>x>>y;
        v1[x].push_back(y);
        v1[y].push_back(x);
 
    }
}
 
void dfs(int x)
{
    viz[x] = true;
 
 
 
    for(int i = 0 ; i <  v1[x].size() ; i ++ )
           if(!viz[v1[x][i]])
               dfs(v1[x][i]);
 
}
 
int main()
{
 
    citire();
 
    int nrc =0 ;
 
    for(int i = 1 ; i <= n ; i++)
        if(!viz[i])
        {
         ++nrc;
            dfs(i);
        }
 
        ofstream out("dfs.out");
        out<<nrc;
 
 
 
    return 0;
}