#include <fstream>
#include <vector>
#include <bits/stdc++.h>

using namespace std;

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

int n , m , x , y , nr;

vector <int> G[100001];
bool viz[100001];

void df(int nod)
{
    for(vector <int> :: iterator it = G[nod].begin() ; it != G[nod].end() ; it ++)
        if(!viz[*it])
        {
            viz[*it] = 1;
            df(*it);
        }
}

int main()
{
    fin >> n >> m;
    for(int i = 1 ; i <= m ; i ++)
    {
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(int i = 1 ; i <= n ; i ++)
        if(!viz[i])
        {
            viz[i] = 1;
            df(i);
            nr ++;
        }
    fout << nr;
    fin.close();
    fout.close();
    return 0;
}