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

using namespace std;

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

int n, m;
vector< int > Vertices[100001];
bool beenThere[100001];

void DFS(int Vertex)
{
    beenThere[Vertex] = true;
    for (int i = 0; i < Vertices[Vertex].size(); i++)
    {
        int neighbour = Vertices[Vertex][i];
        if (beenThere[neighbour] == false)
        {
            DFS(neighbour);
        }
    }
}

int main()
{
    int insule = 0;
    f >> n >> m;
    for (int i = 1; i <= m; i++)
    {
        int x, y;
        f >> x >> y;
        Vertices[x].push_back(y);
        Vertices[y].push_back(x);
    }
    for (int i = 1; i <= n; i++)
    {
        if (beenThere[i] == false)
        {
            insule++;
            DFS(i);
        }
    }
    g << insule;
}