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

using namespace std;

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

vector<vector<int>> g;
vector<bool> vizitat;

void citire(int& n, int& m)
{
    fin >> n >> m;
    g.resize(n+1);
    vizitat.resize(n+1, 0);
    for(int i = 0; i < m; ++i)
    {
        int x, y;
        fin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
}

void dfs(int nod)
{
    vizitat[nod] = 1;
    for(int& v : g[nod])
    {
        if(vizitat[v] == 0)
            dfs(v);
    }
}

int main()
{
    int n, m;
    citire(n, m);
    unsigned c = 0;
    for(int i = 1; i <= n; ++i)
    {
        if(vizitat[i] == 0){
            dfs(i);
            c++;
        }
    }
    fout << c;
    return 0;
}