#include <iostream>
#include <fstream>
#include <cstring>
#include <vector>
#include <queue>


using namespace std;

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

vector < int > v[100005];

int viz[100005] , x , y , n , m , cnt;

void dfs (int nod)
{
    viz[nod] = 1;
    for (int i = 0 ; i < v[nod].size () ; i++)
    {
        if (viz[v[nod][i]] == 0)
            dfs (v[nod][i]);
    }
}

int main()
{
    f >> n >> m;
    for (int i = 1 ; i <= m ; i++)
    {
        f >> x >> y;
        v[x].push_back (y);
        v[y].push_back (x);
    }
    for (int i = 1 ; i <= n ; i++)
    {
        if (viz[i] == 0)
        {
            cnt++;
            dfs (i);
        }
    }
    g << cnt;
    return 0;
}