#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");
const int nlim = 100005;
int n, m;
vector <int> muchii[nlim];
int vizitat[nlim];
int insule;

void dfs(int nod)
{
    vizitat[nod] = 1;
    for(unsigned int i = 0; i < muchii[nod].size(); i++)
    {
        int vecin = muchii[nod][i];
        if(!vizitat[vecin])
            dfs(vecin);
    }
}

void citire()
{
    f>>n>>m;

    for(int i = 1; i <= m; i++)
    {
        int x, y;
        f>>x>>y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }
    for(int i = 1; i <= n; i++)
    {
        if(!vizitat[i])
        {
            insule += 1;
            dfs(i);
        }
    }
}
int main()
{
    citire();
    g<<insule;
    return 0;
}