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

using namespace std;

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

const int nlim = 100005;
int n, m, insule=0;
bool vizitat[nlim];
vector < int > muchii[nlim];

void dfs(int nod)
{
    vizitat[nod] = true;
    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<<'\n';
    return 0;
}