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



int vizitat[2000001], n,m;
vector <int>  a[2000001];

int cont;

void dfs(int v)
{
    vizitat[v] = 1;
    for(const auto &item : a[v])
        if(vizitat[item] == 0)
            dfs(item);
}

int main()
{
    ifstream cin("dfs.in");
    ofstream cout("dfs.out");
    int i, x, y;
    cin >> n >> m;
    for(i = 1; i <= m; i++)
    {
        cin >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for(int i = 1; i <= n; i++)
        if(vizitat[i] == 0)
        {
            cont++;
            dfs(i);
        }
    cout << cont;
    return 0;
}