#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

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

const int MaxN = 100005;

vector <int> V[MaxN];
bool vizitat[MaxN];
int n, m, cnt;

void Citire();
void Dfs(int nod);

int main()
{
    Citire();
    for (int i = 1; i <= n; ++i)
    {
        if (!vizitat[i])
        {
            cnt++;
            Dfs(i);
        }
    }

    fout << cnt;
}
void Dfs(int nod)
{
    vizitat[nod] = true;

    for (int i = 0; i < V[nod].size(); ++i)
    {
        int nou = V[nod][i];
        if (!vizitat[nou])
        {
            Dfs(nou);
        }
    }
}

void Citire()
{
    fin >> n >> m;

    int x, y;
    for (int i = 1; i <= m; ++i)
    {
        fin >> x >> y;
        V[x].push_back(y);
        V[y].push_back(x);
    }
}