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

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

vector<int> v[100001];

int n, m;
int viz[100001];

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

    int x, y;
    for(int i = 0; i < m; ++i)
    {
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}

void dfs(int x)
{
    viz[x] = 1;

    for(int i = 0; i < v[x].size(); i++)
        if(!viz[v[x][i]])
            dfs(v[x][i]);
}

int componente()
{
    int nr = 0;
    for(int i = 1; i <= n; ++i)
        if(!viz[i])
        {
            dfs(i);
            nr++;
        }

    return nr;
}

int main()
{
    citire();
    fout << componente();
    return 0;
}